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cpython/Lib/doctest.py
Edward Loper 19b1958730 Only recognize the expected output as an exception if it *starts* with 
a traceback message.  I.e., examples that raise exceptions may no
longer generate pre-exception output.  This restores the behavior of
doctest in python 2.3.  The ability to check pre-exception output is
being removed because it makes the documentation simpler; and because
there are very few use cases for it.
2004-08-25 23:07:03 +00:00

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# Module doctest.
# Released to the public domain 16-Jan-2001, by Tim Peters (tim@python.org).
# Major enhancements and refactoring by:
# Jim Fulton
# Edward Loper
# Provided as-is; use at your own risk; no warranty; no promises; enjoy!
r"""Module doctest -- a framework for running examples in docstrings.
NORMAL USAGE
In simplest use, end each module M to be tested with:
def _test():
import doctest
return doctest.testmod()
if __name__ == "__main__":
_test()
Then running the module as a script will cause the examples in the
docstrings to get executed and verified:
python M.py
This won't display anything unless an example fails, in which case the
failing example(s) and the cause(s) of the failure(s) are printed to stdout
(why not stderr? because stderr is a lame hack <0.2 wink>), and the final
line of output is "Test failed.".
Run it with the -v switch instead:
python M.py -v
and a detailed report of all examples tried is printed to stdout, along
with assorted summaries at the end.
You can force verbose mode by passing "verbose=True" to testmod, or prohibit
it by passing "verbose=False". In either of those cases, sys.argv is not
examined by testmod.
In any case, testmod returns a 2-tuple of ints (f, t), where f is the
number of docstring examples that failed and t is the total number of
docstring examples attempted.
There are a variety of other ways to run doctests, including integration
with the unittest framework, and support for running non-Python text
files containing doctests. There are also many ways to override parts
of doctest's default behaviors. See the Library Reference Manual for
details.
WHICH DOCSTRINGS ARE EXAMINED?
+ M.__doc__.
+ f.__doc__ for all functions f in M.__dict__.values(), except those
defined in other modules.
+ C.__doc__ for all classes C in M.__dict__.values(), except those
defined in other modules.
+ If M.__test__ exists and "is true", it must be a dict, and
each entry maps a (string) name to a function object, class object, or
string. Function and class object docstrings found from M.__test__
are searched, and strings are searched directly as if they were docstrings.
In output, a key K in M.__test__ appears with name
<name of M>.__test__.K
Any classes found are recursively searched similarly, to test docstrings in
their contained methods and nested classes.
WHAT'S THE EXECUTION CONTEXT?
By default, each time testmod finds a docstring to test, it uses a *copy*
of M's globals (so that running tests on a module doesn't change the
module's real globals, and so that one test in M can't leave behind crumbs
that accidentally allow another test to work). This means examples can
freely use any names defined at top-level in M. It also means that sloppy
imports (see above) can cause examples in external docstrings to use
globals inappropriate for them.
You can force use of your own dict as the execution context by passing
"globs=your_dict" to testmod instead. Presumably this would be a copy of
M.__dict__ merged with the globals from other imported modules.
WHAT ABOUT EXCEPTIONS?
No problem, as long as the only output generated by the example is the
traceback itself. For example:
>>> [1, 2, 3].remove(42)
Traceback (most recent call last):
File "<stdin>", line 1, in ?
ValueError: list.remove(x): x not in list
>>>
Note that only the exception type and value are compared.
SO WHAT DOES A DOCTEST EXAMPLE LOOK LIKE ALREADY!?
Oh ya. It's easy! In most cases a copy-and-paste of an interactive
console session works fine -- just make sure the leading whitespace is
rigidly consistent (you can mix tabs and spaces if you're too lazy to do it
right, but doctest is not in the business of guessing what you think a tab
means).
>>> # comments are ignored
>>> x = 12
>>> x
12
>>> if x == 13:
... print "yes"
... else:
... print "no"
... print "NO"
... print "NO!!!"
...
no
NO
NO!!!
>>>
Any expected output must immediately follow the final ">>>" or "..." line
containing the code, and the expected output (if any) extends to the next
">>>" or all-whitespace line. That's it.
Bummers:
+ Output to stdout is captured, but not output to stderr (exception
tracebacks are captured via a different means).
+ If you continue a line via backslashing in an interactive session,
or for any other reason use a backslash, you should use a raw
docstring, which will preserve your backslahses exactly as you type
them:
>>> def f(x):
... r'''Backslashes in a raw docstring: m\n'''
>>> print f.__doc__
Backslashes in a raw docstring: m\n
Otherwise, the backslash will be interpreted as part of the string.
E.g., the "\n" above would be interpreted as a newline character.
Alternatively, you can double each backslash in the doctest version
(and not use a raw string):
>>> def f(x):
... '''Backslashes in a raw docstring: m\\n'''
>>> print f.__doc__
Backslashes in a raw docstring: m\n
The starting column doesn't matter:
>>> assert "Easy!"
>>> import math
>>> math.floor(1.9)
1.0
and as many leading whitespace characters are stripped from the expected
output as appeared in the initial ">>>" line that triggered it.
If you execute this very file, the examples above will be found and
executed.
"""
__docformat__ = 'reStructuredText en'
__all__ = [
# 0, Option Flags
'register_optionflag',
'DONT_ACCEPT_TRUE_FOR_1',
'DONT_ACCEPT_BLANKLINE',
'NORMALIZE_WHITESPACE',
'ELLIPSIS',
'UNIFIED_DIFF',
'CONTEXT_DIFF',
'NDIFF_DIFF',
# 1. Utility Functions
'is_private',
# 2. Example & DocTest
'Example',
'DocTest',
# 3. Doctest Parser
'DocTestParser',
# 4. Doctest Finder
'DocTestFinder',
# 5. Doctest Runner
'DocTestRunner',
'OutputChecker',
'DocTestFailure',
'UnexpectedException',
'DebugRunner',
# 6. Test Functions
'testmod',
'run_docstring_examples',
# 7. Tester
'Tester',
# 8. Unittest Support
'DocTestCase',
'DocTestSuite',
'DocFileCase',
'DocFileTest',
'DocFileSuite',
# 9. Debugging Support
'script_from_examples',
'testsource',
'debug_src',
'debug_script',
'debug',
]
import __future__
import sys, traceback, inspect, linecache, os, re, types
import unittest, difflib, pdb, tempfile
import warnings
from StringIO import StringIO
# Don't whine about the deprecated is_private function in this
# module's tests.
warnings.filterwarnings("ignore", "is_private", DeprecationWarning,
__name__, 0)
real_pdb_set_trace = pdb.set_trace
# There are 4 basic classes:
# - Example: a <source, want> pair, plus an intra-docstring line number.
# - DocTest: a collection of examples, parsed from a docstring, plus
# info about where the docstring came from (name, filename, lineno).
# - DocTestFinder: extracts DocTests from a given object's docstring and
# its contained objects' docstrings.
# - DocTestRunner: runs DocTest cases, and accumulates statistics.
#
# So the basic picture is:
#
# list of:
# +------+ +---------+ +-------+
# |object| --DocTestFinder-> | DocTest | --DocTestRunner-> |results|
# +------+ +---------+ +-------+
# | Example |
# | ... |
# | Example |
# +---------+
# Option constants.
OPTIONFLAGS_BY_NAME = {}
def register_optionflag(name):
flag = 1 << len(OPTIONFLAGS_BY_NAME)
OPTIONFLAGS_BY_NAME[name] = flag
return flag
DONT_ACCEPT_TRUE_FOR_1 = register_optionflag('DONT_ACCEPT_TRUE_FOR_1')
DONT_ACCEPT_BLANKLINE = register_optionflag('DONT_ACCEPT_BLANKLINE')
NORMALIZE_WHITESPACE = register_optionflag('NORMALIZE_WHITESPACE')
ELLIPSIS = register_optionflag('ELLIPSIS')
UNIFIED_DIFF = register_optionflag('UNIFIED_DIFF')
CONTEXT_DIFF = register_optionflag('CONTEXT_DIFF')
NDIFF_DIFF = register_optionflag('NDIFF_DIFF')
# Special string markers for use in `want` strings:
BLANKLINE_MARKER = '<BLANKLINE>'
ELLIPSIS_MARKER = '...'
######################################################################
## Table of Contents
######################################################################
# 1. Utility Functions
# 2. Example & DocTest -- store test cases
# 3. DocTest Parser -- extracts examples from strings
# 4. DocTest Finder -- extracts test cases from objects
# 5. DocTest Runner -- runs test cases
# 6. Test Functions -- convenient wrappers for testing
# 7. Tester Class -- for backwards compatibility
# 8. Unittest Support
# 9. Debugging Support
# 10. Example Usage
######################################################################
## 1. Utility Functions
######################################################################
def is_private(prefix, base):
"""prefix, base -> true iff name prefix + "." + base is "private".
Prefix may be an empty string, and base does not contain a period.
Prefix is ignored (although functions you write conforming to this
protocol may make use of it).
Return true iff base begins with an (at least one) underscore, but
does not both begin and end with (at least) two underscores.
>>> is_private("a.b", "my_func")
False
>>> is_private("____", "_my_func")
True
>>> is_private("someclass", "__init__")
False
>>> is_private("sometypo", "__init_")
True
>>> is_private("x.y.z", "_")
True
>>> is_private("_x.y.z", "__")
False
>>> is_private("", "") # senseless but consistent
False
"""
warnings.warn("is_private is deprecated; it wasn't useful; "
"examine DocTestFinder.find() lists instead",
DeprecationWarning, stacklevel=2)
return base[:1] == "_" and not base[:2] == "__" == base[-2:]
def _extract_future_flags(globs):
"""
Return the compiler-flags associated with the future features that
have been imported into the given namespace (globs).
"""
flags = 0
for fname in __future__.all_feature_names:
feature = globs.get(fname, None)
if feature is getattr(__future__, fname):
flags |= feature.compiler_flag
return flags
def _normalize_module(module, depth=2):
"""
Return the module specified by `module`. In particular:
- If `module` is a module, then return module.
- If `module` is a string, then import and return the
module with that name.
- If `module` is None, then return the calling module.
The calling module is assumed to be the module of
the stack frame at the given depth in the call stack.
"""
if inspect.ismodule(module):
return module
elif isinstance(module, (str, unicode)):
return __import__(module, globals(), locals(), ["*"])
elif module is None:
return sys.modules[sys._getframe(depth).f_globals['__name__']]
else:
raise TypeError("Expected a module, string, or None")
def _tag_msg(tag, msg, indent=' '):
"""
Return a string that displays a tag-and-message pair nicely,
keeping the tag and its message on the same line when that
makes sense. If the message is displayed on separate lines,
then `indent` is added to the beginning of each line.
"""
# If the message doesn't end in a newline, then add one.
if msg[-1:] != '\n':
msg += '\n'
# If the message is short enough, and contains no internal
# newlines, then display it on the same line as the tag.
# Otherwise, display the tag on its own line.
if (len(tag) + len(msg) < 75 and
msg.find('\n', 0, len(msg)-1) == -1):
return '%s: %s' % (tag, msg)
else:
msg = '\n'.join([indent+l for l in msg[:-1].split('\n')])
return '%s:\n%s\n' % (tag, msg)
def _exception_traceback(exc_info):
"""
Return a string containing a traceback message for the given
exc_info tuple (as returned by sys.exc_info()).
"""
# Get a traceback message.
excout = StringIO()
exc_type, exc_val, exc_tb = exc_info
traceback.print_exception(exc_type, exc_val, exc_tb, file=excout)
return excout.getvalue()
# Override some StringIO methods.
class _SpoofOut(StringIO):
def getvalue(self):
result = StringIO.getvalue(self)
# If anything at all was written, make sure there's a trailing
# newline. There's no way for the expected output to indicate
# that a trailing newline is missing.
if result and not result.endswith("\n"):
result += "\n"
# Prevent softspace from screwing up the next test case, in
# case they used print with a trailing comma in an example.
if hasattr(self, "softspace"):
del self.softspace
return result
def truncate(self, size=None):
StringIO.truncate(self, size)
if hasattr(self, "softspace"):
del self.softspace
# Worst-case linear-time ellipsis matching.
def _ellipsis_match(want, got):
"""
Essentially the only subtle case:
>>> _ellipsis_match('aa...aa', 'aaa')
False
"""
if ELLIPSIS_MARKER not in want:
return want == got
# Find "the real" strings.
ws = want.split(ELLIPSIS_MARKER)
assert len(ws) >= 2
# Deal with exact matches possibly needed at one or both ends.
startpos, endpos = 0, len(got)
w = ws[0]
if w: # starts with exact match
if got.startswith(w):
startpos = len(w)
del ws[0]
else:
return False
w = ws[-1]
if w: # ends with exact match
if got.endswith(w):
endpos -= len(w)
del ws[-1]
else:
return False
if startpos > endpos:
# Exact end matches required more characters than we have, as in
# _ellipsis_match('aa...aa', 'aaa')
return False
# For the rest, we only need to find the leftmost non-overlapping
# match for each piece. If there's no overall match that way alone,
# there's no overall match period.
for w in ws:
# w may be '' at times, if there are consecutive ellipses, or
# due to an ellipsis at the start or end of `want`. That's OK.
# Search for an empty string succeeds, and doesn't change startpos.
startpos = got.find(w, startpos, endpos)
if startpos < 0:
return False
startpos += len(w)
return True
######################################################################
## 2. Example & DocTest
######################################################################
## - An "example" is a <source, want> pair, where "source" is a
## fragment of source code, and "want" is the expected output for
## "source." The Example class also includes information about
## where the example was extracted from.
##
## - A "doctest" is a collection of examples, typically extracted from
## a string (such as an object's docstring). The DocTest class also
## includes information about where the string was extracted from.
class Example:
"""
A single doctest example, consisting of source code and expected
output. `Example` defines the following attributes:
- source: A single Python statement, always ending with a newline.
The constructor adds a newline if needed.
- want: The expected output from running the source code (either
from stdout, or a traceback in case of exception). `want` ends
with a newline unless it's empty, in which case it's an empty
string. The constructor adds a newline if needed.
- lineno: The line number within the DocTest string containing
this Example where the Example begins. This line number is
zero-based, with respect to the beginning of the DocTest.
- indent: The example's indentation in the DocTest string.
I.e., the number of space characters that preceed the
example's first prompt.
- options: A dictionary mapping from option flags to True or
False, which is used to override default options for this
example. Any option flags not contained in this dictionary
are left at their default value (as specified by the
DocTestRunner's optionflags). By default, no options are set.
"""
def __init__(self, source, want, lineno, indent=0, options=None):
# Normalize inputs.
if not source.endswith('\n'):
source += '\n'
if want and not want.endswith('\n'):
want += '\n'
# Store properties.
self.source = source
self.want = want
self.lineno = lineno
self.indent = indent
if options is None: options = {}
self.options = options
class DocTest:
"""
A collection of doctest examples that should be run in a single
namespace. Each `DocTest` defines the following attributes:
- examples: the list of examples.
- globs: The namespace (aka globals) that the examples should
be run in.
- name: A name identifying the DocTest (typically, the name of
the object whose docstring this DocTest was extracted from).
- filename: The name of the file that this DocTest was extracted
from, or `None` if the filename is unknown.
- lineno: The line number within filename where this DocTest
begins, or `None` if the line number is unavailable. This
line number is zero-based, with respect to the beginning of
the file.
- docstring: The string that the examples were extracted from,
or `None` if the string is unavailable.
"""
def __init__(self, examples, globs, name, filename, lineno, docstring):
"""
Create a new DocTest containing the given examples. The
DocTest's globals are initialized with a copy of `globs`.
"""
assert not isinstance(examples, basestring), \
"DocTest no longer accepts str; use DocTestParser instead"
self.examples = examples
self.docstring = docstring
self.globs = globs.copy()
self.name = name
self.filename = filename
self.lineno = lineno
def __repr__(self):
if len(self.examples) == 0:
examples = 'no examples'
elif len(self.examples) == 1:
examples = '1 example'
else:
examples = '%d examples' % len(self.examples)
return ('<DocTest %s from %s:%s (%s)>' %
(self.name, self.filename, self.lineno, examples))
# This lets us sort tests by name:
def __cmp__(self, other):
if not isinstance(other, DocTest):
return -1
return cmp((self.name, self.filename, self.lineno, id(self)),
(other.name, other.filename, other.lineno, id(other)))
######################################################################
## 3. DocTestParser
######################################################################
class DocTestParser:
"""
A class used to parse strings containing doctest examples.
"""
# This regular expression is used to find doctest examples in a
# string. It defines three groups: `source` is the source code
# (including leading indentation and prompts); `indent` is the
# indentation of the first (PS1) line of the source code; and
# `want` is the expected output (including leading indentation).
_EXAMPLE_RE = re.compile(r'''
# Source consists of a PS1 line followed by zero or more PS2 lines.
(?P<source>
(?:^(?P<indent> [ ]*) >>> .*) # PS1 line
(?:\n [ ]* \.\.\. .*)*) # PS2 lines
\n?
# Want consists of any non-blank lines that do not start with PS1.
(?P<want> (?:(?![ ]*$) # Not a blank line
(?![ ]*>>>) # Not a line starting with PS1
.*$\n? # But any other line
)*)
''', re.MULTILINE | re.VERBOSE)
# A callable returning a true value iff its argument is a blank line
# or contains a single comment.
_IS_BLANK_OR_COMMENT = re.compile(r'^[ ]*(#.*)?$').match
def get_doctest(self, string, globs, name, filename, lineno):
"""
Extract all doctest examples from the given string, and
collect them into a `DocTest` object.
`globs`, `name`, `filename`, and `lineno` are attributes for
the new `DocTest` object. See the documentation for `DocTest`
for more information.
"""
return DocTest(self.get_examples(string, name), globs,
name, filename, lineno, string)
def get_examples(self, string, name='<string>'):
"""
Extract all doctest examples from the given string, and return
them as a list of `Example` objects. Line numbers are
0-based, because it's most common in doctests that nothing
interesting appears on the same line as opening triple-quote,
and so the first interesting line is called \"line 1\" then.
The optional argument `name` is a name identifying this
string, and is only used for error messages.
>>> text = '''
... >>> x, y = 2, 3 # no output expected
... >>> if 1:
... ... print x
... ... print y
... 2
... 3
...
... Some text.
... >>> x+y
... 5
... '''
>>> for x in DocTestParser().get_examples(text):
... print (x.source, x.want, x.lineno)
('x, y = 2, 3 # no output expected\\n', '', 1)
('if 1:\\n print x\\n print y\\n', '2\\n3\\n', 2)
('x+y\\n', '5\\n', 9)
"""
examples = []
charno, lineno = 0, 0
# Find all doctest examples in the string:
for m in self._EXAMPLE_RE.finditer(string.expandtabs()):
# Update lineno (lines before this example)
lineno += string.count('\n', charno, m.start())
# Extract source/want from the regexp match.
(source, want) = self._parse_example(m, name, lineno)
# Extract extra options from the source.
options = self._find_options(source, name, lineno)
# Create an Example, and add it to the list.
if not self._IS_BLANK_OR_COMMENT(source):
examples.append( Example(source, want, lineno,
len(m.group('indent')), options) )
# Update lineno (lines inside this example)
lineno += string.count('\n', m.start(), m.end())
# Update charno.
charno = m.end()
return examples
def get_program(self, string, name="<string>"):
"""
Return an executable program from the given string, as a string.
The format of this isn't rigidly defined. In general, doctest
examples become the executable statements in the result, and
their expected outputs become comments, preceded by an \"#Expected:\"
comment. Everything else (text, comments, everything not part of
a doctest test) is also placed in comments.
The optional argument `name` is a name identifying this
string, and is only used for error messages.
>>> text = '''
... >>> x, y = 2, 3 # no output expected
... >>> if 1:
... ... print x
... ... print y
... 2
... 3
...
... Some text.
... >>> x+y
... 5
... '''
>>> print DocTestParser().get_program(text)
x, y = 2, 3 # no output expected
if 1:
print x
print y
# Expected:
## 2
## 3
#
# Some text.
x+y
# Expected:
## 5
"""
string = string.expandtabs()
# If all lines begin with the same indentation, then strip it.
min_indent = self._min_indent(string)
if min_indent > 0:
string = '\n'.join([l[min_indent:] for l in string.split('\n')])
output = []
charnum, lineno = 0, 0
# Find all doctest examples in the string:
for m in self._EXAMPLE_RE.finditer(string.expandtabs()):
# Add any text before this example, as a comment.
if m.start() > charnum:
lines = string[charnum:m.start()-1].split('\n')
output.extend([self._comment_line(l) for l in lines])
lineno += len(lines)
# Extract source/want from the regexp match.
(source, want) = self._parse_example(m, name, lineno)
# Display the source
output.append(source)
# Display the expected output, if any
if want:
output.append('# Expected:')
output.extend(['## '+l for l in want.split('\n')])
# Update the line number & char number.
lineno += string.count('\n', m.start(), m.end())
charnum = m.end()
# Add any remaining text, as comments.
output.extend([self._comment_line(l)
for l in string[charnum:].split('\n')])
# Trim junk on both ends.
while output and output[-1] == '#':
output.pop()
while output and output[0] == '#':
output.pop(0)
# Combine the output, and return it.
return '\n'.join(output)
def _parse_example(self, m, name, lineno):
"""
Given a regular expression match from `_EXAMPLE_RE` (`m`),
return a pair `(source, want)`, where `source` is the matched
example's source code (with prompts and indentation stripped);
and `want` is the example's expected output (with indentation
stripped).
`name` is the string's name, and `lineno` is the line number
where the example starts; both are used for error messages.
"""
# Get the example's indentation level.
indent = len(m.group('indent'))
# Divide source into lines; check that they're properly
# indented; and then strip their indentation & prompts.
source_lines = m.group('source').split('\n')
self._check_prompt_blank(source_lines, indent, name, lineno)
self._check_prefix(source_lines[1:], ' '*indent + '.', name, lineno)
source = '\n'.join([sl[indent+4:] for sl in source_lines])
# Divide want into lines; check that it's properly indented; and
# then strip the indentation. Spaces before the last newline should
# be preserved, so plain rstrip() isn't good enough.
want = m.group('want')
want_lines = want.split('\n')
if len(want_lines) > 1 and re.match(r' *$', want_lines[-1]):
del want_lines[-1] # forget final newline & spaces after it
self._check_prefix(want_lines, ' '*indent, name,
lineno + len(source_lines))
want = '\n'.join([wl[indent:] for wl in want_lines])
return source, want
# This regular expression looks for option directives in the
# source code of an example. Option directives are comments
# starting with "doctest:". Warning: this may give false
# positives for string-literals that contain the string
# "#doctest:". Eliminating these false positives would require
# actually parsing the string; but we limit them by ignoring any
# line containing "#doctest:" that is *followed* by a quote mark.
_OPTION_DIRECTIVE_RE = re.compile(r'#\s*doctest:\s*([^\n\'"]*)$',
re.MULTILINE)
def _find_options(self, source, name, lineno):
"""
Return a dictionary containing option overrides extracted from
option directives in the given source string.
`name` is the string's name, and `lineno` is the line number
where the example starts; both are used for error messages.
"""
options = {}
# (note: with the current regexp, this will match at most once:)
for m in self._OPTION_DIRECTIVE_RE.finditer(source):
option_strings = m.group(1).replace(',', ' ').split()
for option in option_strings:
if (option[0] not in '+-' or
option[1:] not in OPTIONFLAGS_BY_NAME):
raise ValueError('line %r of the doctest for %s '
'has an invalid option: %r' %
(lineno+1, name, option))
flag = OPTIONFLAGS_BY_NAME[option[1:]]
options[flag] = (option[0] == '+')
if options and self._IS_BLANK_OR_COMMENT(source):
raise ValueError('line %r of the doctest for %s has an option '
'directive on a line with no example: %r' %
(lineno, name, source))
return options
# This regular expression finds the indentation of every non-blank
# line in a string.
_INDENT_RE = re.compile('^([ ]+)(?=\S)', re.MULTILINE)
def _min_indent(self, s):
"Return the minimum indentation of any non-blank line in `s`"
return min([len(indent) for indent in self._INDENT_RE.findall(s)])
def _comment_line(self, line):
"Return a commented form of the given line"
line = line.rstrip()
if line:
return '# '+line
else:
return '#'
def _check_prompt_blank(self, lines, indent, name, lineno):
"""
Given the lines of a source string (including prompts and
leading indentation), check to make sure that every prompt is
followed by a space character. If any line is not followed by
a space character, then raise ValueError.
"""
for i, line in enumerate(lines):
if len(line) >= indent+4 and line[indent+3] != ' ':
raise ValueError('line %r of the docstring for %s '
'lacks blank after %s: %r' %
(lineno+i+1, name,
line[indent:indent+3], line))
def _check_prefix(self, lines, prefix, name, lineno):
"""
Check that every line in the given list starts with the given
prefix; if any line does not, then raise a ValueError.
"""
for i, line in enumerate(lines):
if line and not line.startswith(prefix):
raise ValueError('line %r of the docstring for %s has '
'inconsistent leading whitespace: %r' %
(lineno+i+1, name, line))
######################################################################
## 4. DocTest Finder
######################################################################
class DocTestFinder:
"""
A class used to extract the DocTests that are relevant to a given
object, from its docstring and the docstrings of its contained
objects. Doctests can currently be extracted from the following
object types: modules, functions, classes, methods, staticmethods,
classmethods, and properties.
"""
def __init__(self, verbose=False, parser=DocTestParser(),
recurse=True, _namefilter=None):
"""
Create a new doctest finder.
The optional argument `parser` specifies a class or
function that should be used to create new DocTest objects (or
objects that implement the same interface as DocTest). The
signature for this factory function should match the signature
of the DocTest constructor.
If the optional argument `recurse` is false, then `find` will
only examine the given object, and not any contained objects.
"""
self._parser = parser
self._verbose = verbose
self._recurse = recurse
# _namefilter is undocumented, and exists only for temporary backward-
# compatibility support of testmod's deprecated isprivate mess.
self._namefilter = _namefilter
def find(self, obj, name=None, module=None, globs=None,
extraglobs=None):
"""
Return a list of the DocTests that are defined by the given
object's docstring, or by any of its contained objects'
docstrings.
The optional parameter `module` is the module that contains
the given object. If the module is not specified or is None, then
the test finder will attempt to automatically determine the
correct module. The object's module is used:
- As a default namespace, if `globs` is not specified.
- To prevent the DocTestFinder from extracting DocTests
from objects that are imported from other modules.
- To find the name of the file containing the object.
- To help find the line number of the object within its
file.
Contained objects whose module does not match `module` are ignored.
If `module` is False, no attempt to find the module will be made.
This is obscure, of use mostly in tests: if `module` is False, or
is None but cannot be found automatically, then all objects are
considered to belong to the (non-existent) module, so all contained
objects will (recursively) be searched for doctests.
The globals for each DocTest is formed by combining `globs`
and `extraglobs` (bindings in `extraglobs` override bindings
in `globs`). A new copy of the globals dictionary is created
for each DocTest. If `globs` is not specified, then it
defaults to the module's `__dict__`, if specified, or {}
otherwise. If `extraglobs` is not specified, then it defaults
to {}.
"""
# If name was not specified, then extract it from the object.
if name is None:
name = getattr(obj, '__name__', None)
if name is None:
raise ValueError("DocTestFinder.find: name must be given "
"when obj.__name__ doesn't exist: %r" %
(type(obj),))
# Find the module that contains the given object (if obj is
# a module, then module=obj.). Note: this may fail, in which
# case module will be None.
if module is False:
module = None
elif module is None:
module = inspect.getmodule(obj)
# Read the module's source code. This is used by
# DocTestFinder._find_lineno to find the line number for a
# given object's docstring.
try:
file = inspect.getsourcefile(obj) or inspect.getfile(obj)
source_lines = linecache.getlines(file)
if not source_lines:
source_lines = None
except TypeError:
source_lines = None
# Initialize globals, and merge in extraglobs.
if globs is None:
if module is None:
globs = {}
else:
globs = module.__dict__.copy()
else:
globs = globs.copy()
if extraglobs is not None:
globs.update(extraglobs)
# Recursively expore `obj`, extracting DocTests.
tests = []
self._find(tests, obj, name, module, source_lines, globs, {})
return tests
def _filter(self, obj, prefix, base):
"""
Return true if the given object should not be examined.
"""
return (self._namefilter is not None and
self._namefilter(prefix, base))
def _from_module(self, module, object):
"""
Return true if the given object is defined in the given
module.
"""
if module is None:
return True
elif inspect.isfunction(object):
return module.__dict__ is object.func_globals
elif inspect.isclass(object):
return module.__name__ == object.__module__
elif inspect.getmodule(object) is not None:
return module is inspect.getmodule(object)
elif hasattr(object, '__module__'):
return module.__name__ == object.__module__
elif isinstance(object, property):
return True # [XX] no way not be sure.
else:
raise ValueError("object must be a class or function")
def _find(self, tests, obj, name, module, source_lines, globs, seen):
"""
Find tests for the given object and any contained objects, and
add them to `tests`.
"""
if self._verbose:
print 'Finding tests in %s' % name
# If we've already processed this object, then ignore it.
if id(obj) in seen:
return
seen[id(obj)] = 1
# Find a test for this object, and add it to the list of tests.
test = self._get_test(obj, name, module, globs, source_lines)
if test is not None:
tests.append(test)
# Look for tests in a module's contained objects.
if inspect.ismodule(obj) and self._recurse:
for valname, val in obj.__dict__.items():
# Check if this contained object should be ignored.
if self._filter(val, name, valname):
continue
valname = '%s.%s' % (name, valname)
# Recurse to functions & classes.
if ((inspect.isfunction(val) or inspect.isclass(val)) and
self._from_module(module, val)):
self._find(tests, val, valname, module, source_lines,
globs, seen)
# Look for tests in a module's __test__ dictionary.
if inspect.ismodule(obj) and self._recurse:
for valname, val in getattr(obj, '__test__', {}).items():
if not isinstance(valname, basestring):
raise ValueError("DocTestFinder.find: __test__ keys "
"must be strings: %r" %
(type(valname),))
if not (inspect.isfunction(val) or inspect.isclass(val) or
inspect.ismethod(val) or inspect.ismodule(val) or
isinstance(val, basestring)):
raise ValueError("DocTestFinder.find: __test__ values "
"must be strings, functions, methods, "
"classes, or modules: %r" %
(type(val),))
valname = '%s.%s' % (name, valname)
self._find(tests, val, valname, module, source_lines,
globs, seen)
# Look for tests in a class's contained objects.
if inspect.isclass(obj) and self._recurse:
for valname, val in obj.__dict__.items():
# Check if this contained object should be ignored.
if self._filter(val, name, valname):
continue
# Special handling for staticmethod/classmethod.
if isinstance(val, staticmethod):
val = getattr(obj, valname)
if isinstance(val, classmethod):
val = getattr(obj, valname).im_func
# Recurse to methods, properties, and nested classes.
if ((inspect.isfunction(val) or inspect.isclass(val) or
isinstance(val, property)) and
self._from_module(module, val)):
valname = '%s.%s' % (name, valname)
self._find(tests, val, valname, module, source_lines,
globs, seen)
def _get_test(self, obj, name, module, globs, source_lines):
"""
Return a DocTest for the given object, if it defines a docstring;
otherwise, return None.
"""
# Extract the object's docstring. If it doesn't have one,
# then return None (no test for this object).
if isinstance(obj, basestring):
docstring = obj
else:
try:
if obj.__doc__ is None:
return None
docstring = str(obj.__doc__)
except (TypeError, AttributeError):
return None
# Don't bother if the docstring is empty.
if not docstring:
return None
# Find the docstring's location in the file.
lineno = self._find_lineno(obj, source_lines)
# Return a DocTest for this object.
if module is None:
filename = None
else:
filename = getattr(module, '__file__', module.__name__)
if filename[-4:] in (".pyc", ".pyo"):
filename = filename[:-1]
return self._parser.get_doctest(docstring, globs, name,
filename, lineno)
def _find_lineno(self, obj, source_lines):
"""
Return a line number of the given object's docstring. Note:
this method assumes that the object has a docstring.
"""
lineno = None
# Find the line number for modules.
if inspect.ismodule(obj):
lineno = 0
# Find the line number for classes.
# Note: this could be fooled if a class is defined multiple
# times in a single file.
if inspect.isclass(obj):
if source_lines is None:
return None
pat = re.compile(r'^\s*class\s*%s\b' %
getattr(obj, '__name__', '-'))
for i, line in enumerate(source_lines):
if pat.match(line):
lineno = i
break
# Find the line number for functions & methods.
if inspect.ismethod(obj): obj = obj.im_func
if inspect.isfunction(obj): obj = obj.func_code
if inspect.istraceback(obj): obj = obj.tb_frame
if inspect.isframe(obj): obj = obj.f_code
if inspect.iscode(obj):
lineno = getattr(obj, 'co_firstlineno', None)-1
# Find the line number where the docstring starts. Assume
# that it's the first line that begins with a quote mark.
# Note: this could be fooled by a multiline function
# signature, where a continuation line begins with a quote
# mark.
if lineno is not None:
if source_lines is None:
return lineno+1
pat = re.compile('(^|.*:)\s*\w*("|\')')
for lineno in range(lineno, len(source_lines)):
if pat.match(source_lines[lineno]):
return lineno
# We couldn't find the line number.
return None
######################################################################
## 5. DocTest Runner
######################################################################
class DocTestRunner:
"""
A class used to run DocTest test cases, and accumulate statistics.
The `run` method is used to process a single DocTest case. It
returns a tuple `(f, t)`, where `t` is the number of test cases
tried, and `f` is the number of test cases that failed.
>>> tests = DocTestFinder().find(_TestClass)
>>> runner = DocTestRunner(verbose=False)
>>> for test in tests:
... print runner.run(test)
(0, 2)
(0, 1)
(0, 2)
(0, 2)
The `summarize` method prints a summary of all the test cases that
have been run by the runner, and returns an aggregated `(f, t)`
tuple:
>>> runner.summarize(verbose=1)
4 items passed all tests:
2 tests in _TestClass
2 tests in _TestClass.__init__
2 tests in _TestClass.get
1 tests in _TestClass.square
7 tests in 4 items.
7 passed and 0 failed.
Test passed.
(0, 7)
The aggregated number of tried examples and failed examples is
also available via the `tries` and `failures` attributes:
>>> runner.tries
7
>>> runner.failures
0
The comparison between expected outputs and actual outputs is done
by an `OutputChecker`. This comparison may be customized with a
number of option flags; see the documentation for `testmod` for
more information. If the option flags are insufficient, then the
comparison may also be customized by passing a subclass of
`OutputChecker` to the constructor.
The test runner's display output can be controlled in two ways.
First, an output function (`out) can be passed to
`TestRunner.run`; this function will be called with strings that
should be displayed. It defaults to `sys.stdout.write`. If
capturing the output is not sufficient, then the display output
can be also customized by subclassing DocTestRunner, and
overriding the methods `report_start`, `report_success`,
`report_unexpected_exception`, and `report_failure`.
"""
# This divider string is used to separate failure messages, and to
# separate sections of the summary.
DIVIDER = "*" * 70
def __init__(self, checker=None, verbose=None, optionflags=0):
"""
Create a new test runner.
Optional keyword arg `checker` is the `OutputChecker` that
should be used to compare the expected outputs and actual
outputs of doctest examples.
Optional keyword arg 'verbose' prints lots of stuff if true,
only failures if false; by default, it's true iff '-v' is in
sys.argv.
Optional argument `optionflags` can be used to control how the
test runner compares expected output to actual output, and how
it displays failures. See the documentation for `testmod` for
more information.
"""
self._checker = checker or OutputChecker()
if verbose is None:
verbose = '-v' in sys.argv
self._verbose = verbose
self.optionflags = optionflags
self.original_optionflags = optionflags
# Keep track of the examples we've run.
self.tries = 0
self.failures = 0
self._name2ft = {}
# Create a fake output target for capturing doctest output.
self._fakeout = _SpoofOut()
#/////////////////////////////////////////////////////////////////
# Reporting methods
#/////////////////////////////////////////////////////////////////
def report_start(self, out, test, example):
"""
Report that the test runner is about to process the given
example. (Only displays a message if verbose=True)
"""
if self._verbose:
out(_tag_msg("Trying", example.source) +
_tag_msg("Expecting", example.want or "nothing"))
def report_success(self, out, test, example, got):
"""
Report that the given example ran successfully. (Only
displays a message if verbose=True)
"""
if self._verbose:
out("ok\n")
def report_failure(self, out, test, example, got):
"""
Report that the given example failed.
"""
# Print an error message.
out(self._failure_header(test, example) +
self._checker.output_difference(example.want, got,
self.optionflags))
def report_unexpected_exception(self, out, test, example, exc_info):
"""
Report that the given example raised an unexpected exception.
"""
out(self._failure_header(test, example) +
_tag_msg("Exception raised", _exception_traceback(exc_info)))
def _failure_header(self, test, example):
out = [self.DIVIDER]
if test.filename:
if test.lineno is not None and example.lineno is not None:
lineno = test.lineno + example.lineno + 1
else:
lineno = '?'
out.append('File "%s", line %s, in %s' %
(test.filename, lineno, test.name))
else:
out.append('Line %s, in %s' % (example.lineno+1, test.name))
out.append('Failed example:')
source = example.source
if source.endswith('\n'):
source = source[:-1]
out.append(' ' + '\n '.join(source.split('\n')))
return '\n'.join(out)+'\n'
#/////////////////////////////////////////////////////////////////
# DocTest Running
#/////////////////////////////////////////////////////////////////
# A regular expression for handling `want` strings that contain
# expected exceptions. It divides `want` into three pieces:
# - the traceback header line (`hdr`)
# - the traceback stack (`stack`)
# - the exception message (`msg`), as generated by
# traceback.format_exception_only()
# `msg` may have multiple lines. We assume/require that the
# exception message is the first non-indented line starting with a word
# character following the traceback header line.
_EXCEPTION_RE = re.compile(r"""
# Grab the traceback header. Different versions of Python have
# said different things on the first traceback line.
^(?P<hdr> Traceback\ \(
(?: most\ recent\ call\ last
| innermost\ last
) \) :
)
\s* $ # toss trailing whitespace on the header.
(?P<stack> .*?) # don't blink: absorb stuff until...
^ (?P<msg> \w+ .*) # a line *starts* with alphanum.
""", re.VERBOSE | re.MULTILINE | re.DOTALL)
def __run(self, test, compileflags, out):
"""
Run the examples in `test`. Write the outcome of each example
with one of the `DocTestRunner.report_*` methods, using the
writer function `out`. `compileflags` is the set of compiler
flags that should be used to execute examples. Return a tuple
`(f, t)`, where `t` is the number of examples tried, and `f`
is the number of examples that failed. The examples are run
in the namespace `test.globs`.
"""
# Keep track of the number of failures and tries.
failures = tries = 0
# Save the option flags (since option directives can be used
# to modify them).
original_optionflags = self.optionflags
# Process each example.
for example in test.examples:
# Merge in the example's options.
self.optionflags = original_optionflags
if example.options:
for (optionflag, val) in example.options.items():
if val:
self.optionflags |= optionflag
else:
self.optionflags &= ~optionflag
# Record that we started this example.
tries += 1
self.report_start(out, test, example)
# Run the example in the given context (globs), and record
# any exception that gets raised. (But don't intercept
# keyboard interrupts.)
try:
# Don't blink! This is where the user's code gets run.
exec compile(example.source, "<string>", "single",
compileflags, 1) in test.globs
exception = None
except KeyboardInterrupt:
raise
except:
exception = sys.exc_info()
got = self._fakeout.getvalue() # the actual output
self._fakeout.truncate(0)
# If the example executed without raising any exceptions,
# then verify its output and report its outcome.
if exception is None:
if self._checker.check_output(example.want, got,
self.optionflags):
self.report_success(out, test, example, got)
else:
self.report_failure(out, test, example, got)
failures += 1
# If the example raised an exception, then check if it was
# expected.
else:
exc_info = sys.exc_info()
exc_msg = traceback.format_exception_only(*exc_info[:2])[-1]
# Search the `want` string for an exception. If we don't
# find one, then report an unexpected exception.
m = self._EXCEPTION_RE.match(example.want)
if m is None:
self.report_unexpected_exception(out, test, example,
exc_info)
failures += 1
else:
# The test passes iff the expected exception
# message (`m.group('msg')`) matches the actual
# exception message (`exc_msg`).
if (self._checker.check_output(m.group('msg'), exc_msg,
self.optionflags)):
self.report_success(out, test, example,
got + _exception_traceback(exc_info))
else:
self.report_failure(out, test, example,
got + _exception_traceback(exc_info))
failures += 1
# Restore the option flags (in case they were modified)
self.optionflags = original_optionflags
# Record and return the number of failures and tries.
self.__record_outcome(test, failures, tries)
return failures, tries
def __record_outcome(self, test, f, t):
"""
Record the fact that the given DocTest (`test`) generated `f`
failures out of `t` tried examples.
"""
f2, t2 = self._name2ft.get(test.name, (0,0))
self._name2ft[test.name] = (f+f2, t+t2)
self.failures += f
self.tries += t
def run(self, test, compileflags=None, out=None, clear_globs=True):
"""
Run the examples in `test`, and display the results using the
writer function `out`.
The examples are run in the namespace `test.globs`. If
`clear_globs` is true (the default), then this namespace will
be cleared after the test runs, to help with garbage
collection. If you would like to examine the namespace after
the test completes, then use `clear_globs=False`.
`compileflags` gives the set of flags that should be used by
the Python compiler when running the examples. If not
specified, then it will default to the set of future-import
flags that apply to `globs`.
The output of each example is checked using
`DocTestRunner.check_output`, and the results are formatted by
the `DocTestRunner.report_*` methods.
"""
if compileflags is None:
compileflags = _extract_future_flags(test.globs)
save_stdout = sys.stdout
if out is None:
out = save_stdout.write
sys.stdout = self._fakeout
# Patch pdb.set_trace to restore sys.stdout, so that interactive
# debugging output is visible (not still redirected to self._fakeout).
# Note that we run "the real" pdb.set_trace (captured at doctest
# import time) in our replacement. Because the current run() may
# run another doctest (and so on), the current pdb.set_trace may be
# our set_trace function, which changes sys.stdout. If we called
# a chain of those, we wouldn't be left with the save_stdout
# *this* run() invocation wants.
def set_trace():
sys.stdout = save_stdout
real_pdb_set_trace()
save_set_trace = pdb.set_trace
pdb.set_trace = set_trace
try:
return self.__run(test, compileflags, out)
finally:
sys.stdout = save_stdout
pdb.set_trace = save_set_trace
if clear_globs:
test.globs.clear()
#/////////////////////////////////////////////////////////////////
# Summarization
#/////////////////////////////////////////////////////////////////
def summarize(self, verbose=None):
"""
Print a summary of all the test cases that have been run by
this DocTestRunner, and return a tuple `(f, t)`, where `f` is
the total number of failed examples, and `t` is the total
number of tried examples.
The optional `verbose` argument controls how detailed the
summary is. If the verbosity is not specified, then the
DocTestRunner's verbosity is used.
"""
if verbose is None:
verbose = self._verbose
notests = []
passed = []
failed = []
totalt = totalf = 0
for x in self._name2ft.items():
name, (f, t) = x
assert f <= t
totalt += t
totalf += f
if t == 0:
notests.append(name)
elif f == 0:
passed.append( (name, t) )
else:
failed.append(x)
if verbose:
if notests:
print len(notests), "items had no tests:"
notests.sort()
for thing in notests:
print " ", thing
if passed:
print len(passed), "items passed all tests:"
passed.sort()
for thing, count in passed:
print " %3d tests in %s" % (count, thing)
if failed:
print self.DIVIDER
print len(failed), "items had failures:"
failed.sort()
for thing, (f, t) in failed:
print " %3d of %3d in %s" % (f, t, thing)
if verbose:
print totalt, "tests in", len(self._name2ft), "items."
print totalt - totalf, "passed and", totalf, "failed."
if totalf:
print "***Test Failed***", totalf, "failures."
elif verbose:
print "Test passed."
return totalf, totalt
class OutputChecker:
"""
A class used to check the whether the actual output from a doctest
example matches the expected output. `OutputChecker` defines two
methods: `check_output`, which compares a given pair of outputs,
and returns true if they match; and `output_difference`, which
returns a string describing the differences between two outputs.
"""
def check_output(self, want, got, optionflags):
"""
Return True iff the actual output from an example (`got`)
matches the expected output (`want`). These strings are
always considered to match if they are identical; but
depending on what option flags the test runner is using,
several non-exact match types are also possible. See the
documentation for `TestRunner` for more information about
option flags.
"""
# Handle the common case first, for efficiency:
# if they're string-identical, always return true.
if got == want:
return True
# The values True and False replaced 1 and 0 as the return
# value for boolean comparisons in Python 2.3.
if not (optionflags & DONT_ACCEPT_TRUE_FOR_1):
if (got,want) == ("True\n", "1\n"):
return True
if (got,want) == ("False\n", "0\n"):
return True
# <BLANKLINE> can be used as a special sequence to signify a
# blank line, unless the DONT_ACCEPT_BLANKLINE flag is used.
if not (optionflags & DONT_ACCEPT_BLANKLINE):
# Replace <BLANKLINE> in want with a blank line.
want = re.sub('(?m)^%s\s*?$' % re.escape(BLANKLINE_MARKER),
'', want)
# If a line in got contains only spaces, then remove the
# spaces.
got = re.sub('(?m)^\s*?$', '', got)
if got == want:
return True
# This flag causes doctest to ignore any differences in the
# contents of whitespace strings. Note that this can be used
# in conjunction with the ELLIPSIS flag.
if optionflags & NORMALIZE_WHITESPACE:
got = ' '.join(got.split())
want = ' '.join(want.split())
if got == want:
return True
# The ELLIPSIS flag says to let the sequence "..." in `want`
# match any substring in `got`.
if optionflags & ELLIPSIS:
if _ellipsis_match(want, got):
return True
# We didn't find any match; return false.
return False
# Should we do a fancy diff?
def _do_a_fancy_diff(self, want, got, optionflags):
# Not unless they asked for a fancy diff.
if not optionflags & (UNIFIED_DIFF |
CONTEXT_DIFF |
NDIFF_DIFF):
return False
# If expected output uses ellipsis, a meaningful fancy diff is
# too hard.
if optionflags & ELLIPSIS and ELLIPSIS_MARKER in want:
return False
# ndiff does intraline difference marking, so can be useful even
# for 1-line inputs.
if optionflags & NDIFF_DIFF:
return True
# The other diff types need at least a few lines to be helpful.
return want.count('\n') > 2 and got.count('\n') > 2
def output_difference(self, want, got, optionflags):
"""
Return a string describing the differences between the
expected output for an example (`want`) and the actual output
(`got`). `optionflags` is the set of option flags used to
compare `want` and `got`. `indent` is the indentation of the
original example.
"""
# If <BLANKLINE>s are being used, then replace blank lines
# with <BLANKLINE> in the actual output string.
if not (optionflags & DONT_ACCEPT_BLANKLINE):
got = re.sub('(?m)^[ ]*(?=\n)', BLANKLINE_MARKER, got)
# Check if we should use diff. Don't use diff if the actual
# or expected outputs are too short, or if the expected output
# contains an ellipsis marker.
if self._do_a_fancy_diff(want, got, optionflags):
# Split want & got into lines.
want_lines = [l+'\n' for l in want.split('\n')]
got_lines = [l+'\n' for l in got.split('\n')]
# Use difflib to find their differences.
if optionflags & UNIFIED_DIFF:
diff = difflib.unified_diff(want_lines, got_lines, n=2,
fromfile='Expected', tofile='Got')
kind = 'unified diff'
elif optionflags & CONTEXT_DIFF:
diff = difflib.context_diff(want_lines, got_lines, n=2,
fromfile='Expected', tofile='Got')
kind = 'context diff'
elif optionflags & NDIFF_DIFF:
engine = difflib.Differ(charjunk=difflib.IS_CHARACTER_JUNK)
diff = list(engine.compare(want_lines, got_lines))
kind = 'ndiff with -expected +actual'
else:
assert 0, 'Bad diff option'
# Remove trailing whitespace on diff output.
diff = [line.rstrip() + '\n' for line in diff]
return _tag_msg("Differences (" + kind + ")",
''.join(diff))
# If we're not using diff, then simply list the expected
# output followed by the actual output.
if want.endswith('\n'):
want = want[:-1]
want = ' ' + '\n '.join(want.split('\n'))
if got.endswith('\n'):
got = got[:-1]
got = ' ' + '\n '.join(got.split('\n'))
return "Expected:\n%s\nGot:\n%s\n" % (want, got)
class DocTestFailure(Exception):
"""A DocTest example has failed in debugging mode.
The exception instance has variables:
- test: the DocTest object being run
- excample: the Example object that failed
- got: the actual output
"""
def __init__(self, test, example, got):
self.test = test
self.example = example
self.got = got
def __str__(self):
return str(self.test)
class UnexpectedException(Exception):
"""A DocTest example has encountered an unexpected exception
The exception instance has variables:
- test: the DocTest object being run
- excample: the Example object that failed
- exc_info: the exception info
"""
def __init__(self, test, example, exc_info):
self.test = test
self.example = example
self.exc_info = exc_info
def __str__(self):
return str(self.test)
class DebugRunner(DocTestRunner):
r"""Run doc tests but raise an exception as soon as there is a failure.
If an unexpected exception occurs, an UnexpectedException is raised.
It contains the test, the example, and the original exception:
>>> runner = DebugRunner(verbose=False)
>>> test = DocTestParser().get_doctest('>>> raise KeyError\n42',
... {}, 'foo', 'foo.py', 0)
>>> try:
... runner.run(test)
... except UnexpectedException, failure:
... pass
>>> failure.test is test
True
>>> failure.example.want
'42\n'
>>> exc_info = failure.exc_info
>>> raise exc_info[0], exc_info[1], exc_info[2]
Traceback (most recent call last):
...
KeyError
We wrap the original exception to give the calling application
access to the test and example information.
If the output doesn't match, then a DocTestFailure is raised:
>>> test = DocTestParser().get_doctest('''
... >>> x = 1
... >>> x
... 2
... ''', {}, 'foo', 'foo.py', 0)
>>> try:
... runner.run(test)
... except DocTestFailure, failure:
... pass
DocTestFailure objects provide access to the test:
>>> failure.test is test
True
As well as to the example:
>>> failure.example.want
'2\n'
and the actual output:
>>> failure.got
'1\n'
If a failure or error occurs, the globals are left intact:
>>> del test.globs['__builtins__']
>>> test.globs
{'x': 1}
>>> test = DocTestParser().get_doctest('''
... >>> x = 2
... >>> raise KeyError
... ''', {}, 'foo', 'foo.py', 0)
>>> runner.run(test)
Traceback (most recent call last):
...
UnexpectedException: <DocTest foo from foo.py:0 (2 examples)>
>>> del test.globs['__builtins__']
>>> test.globs
{'x': 2}
But the globals are cleared if there is no error:
>>> test = DocTestParser().get_doctest('''
... >>> x = 2
... ''', {}, 'foo', 'foo.py', 0)
>>> runner.run(test)
(0, 1)
>>> test.globs
{}
"""
def run(self, test, compileflags=None, out=None, clear_globs=True):
r = DocTestRunner.run(self, test, compileflags, out, False)
if clear_globs:
test.globs.clear()
return r
def report_unexpected_exception(self, out, test, example, exc_info):
raise UnexpectedException(test, example, exc_info)
def report_failure(self, out, test, example, got):
raise DocTestFailure(test, example, got)
######################################################################
## 6. Test Functions
######################################################################
# These should be backwards compatible.
def testmod(m=None, name=None, globs=None, verbose=None, isprivate=None,
report=True, optionflags=0, extraglobs=None,
raise_on_error=False):
"""m=None, name=None, globs=None, verbose=None, isprivate=None,
report=True, optionflags=0, extraglobs=None
Test examples in docstrings in functions and classes reachable
from module m (or the current module if m is not supplied), starting
with m.__doc__. Unless isprivate is specified, private names
are not skipped.
Also test examples reachable from dict m.__test__ if it exists and is
not None. m.__test__ maps names to functions, classes and strings;
function and class docstrings are tested even if the name is private;
strings are tested directly, as if they were docstrings.
Return (#failures, #tests).
See doctest.__doc__ for an overview.
Optional keyword arg "name" gives the name of the module; by default
use m.__name__.
Optional keyword arg "globs" gives a dict to be used as the globals
when executing examples; by default, use m.__dict__. A copy of this
dict is actually used for each docstring, so that each docstring's
examples start with a clean slate.
Optional keyword arg "extraglobs" gives a dictionary that should be
merged into the globals that are used to execute examples. By
default, no extra globals are used. This is new in 2.4.
Optional keyword arg "verbose" prints lots of stuff if true, prints
only failures if false; by default, it's true iff "-v" is in sys.argv.
Optional keyword arg "report" prints a summary at the end when true,
else prints nothing at the end. In verbose mode, the summary is
detailed, else very brief (in fact, empty if all tests passed).
Optional keyword arg "optionflags" or's together module constants,
and defaults to 0. This is new in 2.3. Possible values (see the
docs for details):
DONT_ACCEPT_TRUE_FOR_1
DONT_ACCEPT_BLANKLINE
NORMALIZE_WHITESPACE
ELLIPSIS
UNIFIED_DIFF
CONTEXT_DIFF
NDIFF_DIFF
Optional keyword arg "raise_on_error" raises an exception on the
first unexpected exception or failure. This allows failures to be
post-mortem debugged.
Deprecated in Python 2.4:
Optional keyword arg "isprivate" specifies a function used to
determine whether a name is private. The default function is
treat all functions as public. Optionally, "isprivate" can be
set to doctest.is_private to skip over functions marked as private
using the underscore naming convention; see its docs for details.
"""
""" [XX] This is no longer true:
Advanced tomfoolery: testmod runs methods of a local instance of
class doctest.Tester, then merges the results into (or creates)
global Tester instance doctest.master. Methods of doctest.master
can be called directly too, if you want to do something unusual.
Passing report=0 to testmod is especially useful then, to delay
displaying a summary. Invoke doctest.master.summarize(verbose)
when you're done fiddling.
"""
if isprivate is not None:
warnings.warn("the isprivate argument is deprecated; "
"examine DocTestFinder.find() lists instead",
DeprecationWarning)
# If no module was given, then use __main__.
if m is None:
# DWA - m will still be None if this wasn't invoked from the command
# line, in which case the following TypeError is about as good an error
# as we should expect
m = sys.modules.get('__main__')
# Check that we were actually given a module.
if not inspect.ismodule(m):
raise TypeError("testmod: module required; %r" % (m,))
# If no name was given, then use the module's name.
if name is None:
name = m.__name__
# Find, parse, and run all tests in the given module.
finder = DocTestFinder(_namefilter=isprivate)
if raise_on_error:
runner = DebugRunner(verbose=verbose, optionflags=optionflags)
else:
runner = DocTestRunner(verbose=verbose, optionflags=optionflags)
for test in finder.find(m, name, globs=globs, extraglobs=extraglobs):
runner.run(test)
if report:
runner.summarize()
return runner.failures, runner.tries
def run_docstring_examples(f, globs, verbose=False, name="NoName",
compileflags=None, optionflags=0):
"""
Test examples in the given object's docstring (`f`), using `globs`
as globals. Optional argument `name` is used in failure messages.
If the optional argument `verbose` is true, then generate output
even if there are no failures.
`compileflags` gives the set of flags that should be used by the
Python compiler when running the examples. If not specified, then
it will default to the set of future-import flags that apply to
`globs`.
Optional keyword arg `optionflags` specifies options for the
testing and output. See the documentation for `testmod` for more
information.
"""
# Find, parse, and run all tests in the given module.
finder = DocTestFinder(verbose=verbose, recurse=False)
runner = DocTestRunner(verbose=verbose, optionflags=optionflags)
for test in finder.find(f, name, globs=globs):
runner.run(test, compileflags=compileflags)
######################################################################
## 7. Tester
######################################################################
# This is provided only for backwards compatibility. It's not
# actually used in any way.
class Tester:
def __init__(self, mod=None, globs=None, verbose=None,
isprivate=None, optionflags=0):
warnings.warn("class Tester is deprecated; "
"use class doctest.DocTestRunner instead",
DeprecationWarning, stacklevel=2)
if mod is None and globs is None:
raise TypeError("Tester.__init__: must specify mod or globs")
if mod is not None and not _ismodule(mod):
raise TypeError("Tester.__init__: mod must be a module; %r" %
(mod,))
if globs is None:
globs = mod.__dict__
self.globs = globs
self.verbose = verbose
self.isprivate = isprivate
self.optionflags = optionflags
self.testfinder = DocTestFinder(_namefilter=isprivate)
self.testrunner = DocTestRunner(verbose=verbose,
optionflags=optionflags)
def runstring(self, s, name):
test = DocTestParser().get_doctest(s, self.globs, name, None, None)
if self.verbose:
print "Running string", name
(f,t) = self.testrunner.run(test)
if self.verbose:
print f, "of", t, "examples failed in string", name
return (f,t)
def rundoc(self, object, name=None, module=None):
f = t = 0
tests = self.testfinder.find(object, name, module=module,
globs=self.globs)
for test in tests:
(f2, t2) = self.testrunner.run(test)
(f,t) = (f+f2, t+t2)
return (f,t)
def rundict(self, d, name, module=None):
import new
m = new.module(name)
m.__dict__.update(d)
if module is None:
module = False
return self.rundoc(m, name, module)
def run__test__(self, d, name):
import new
m = new.module(name)
m.__test__ = d
return self.rundoc(m, name, module)
def summarize(self, verbose=None):
return self.testrunner.summarize(verbose)
def merge(self, other):
d = self.testrunner._name2ft
for name, (f, t) in other.testrunner._name2ft.items():
if name in d:
print "*** Tester.merge: '" + name + "' in both" \
" testers; summing outcomes."
f2, t2 = d[name]
f = f + f2
t = t + t2
d[name] = f, t
######################################################################
## 8. Unittest Support
######################################################################
class DocTestCase(unittest.TestCase):
def __init__(self, test, optionflags=0, setUp=None, tearDown=None,
checker=None):
unittest.TestCase.__init__(self)
self._dt_optionflags = optionflags
self._dt_checker = checker
self._dt_test = test
self._dt_setUp = setUp
self._dt_tearDown = tearDown
def setUp(self):
if self._dt_setUp is not None:
self._dt_setUp()
def tearDown(self):
if self._dt_tearDown is not None:
self._dt_tearDown()
def runTest(self):
test = self._dt_test
old = sys.stdout
new = StringIO()
runner = DocTestRunner(optionflags=self._dt_optionflags,
checker=self._dt_checker, verbose=False)
try:
runner.DIVIDER = "-"*70
failures, tries = runner.run(test, out=new.write)
finally:
sys.stdout = old
if failures:
raise self.failureException(self.format_failure(new.getvalue()))
def format_failure(self, err):
test = self._dt_test
if test.lineno is None:
lineno = 'unknown line number'
else:
lineno = '%s' % test.lineno
lname = '.'.join(test.name.split('.')[-1:])
return ('Failed doctest test for %s\n'
' File "%s", line %s, in %s\n\n%s'
% (test.name, test.filename, lineno, lname, err)
)
def debug(self):
r"""Run the test case without results and without catching exceptions
The unit test framework includes a debug method on test cases
and test suites to support post-mortem debugging. The test code
is run in such a way that errors are not caught. This way a
caller can catch the errors and initiate post-mortem debugging.
The DocTestCase provides a debug method that raises
UnexpectedException errors if there is an unexepcted
exception:
>>> test = DocTestParser().get_doctest('>>> raise KeyError\n42',
... {}, 'foo', 'foo.py', 0)
>>> case = DocTestCase(test)
>>> try:
... case.debug()
... except UnexpectedException, failure:
... pass
The UnexpectedException contains the test, the example, and
the original exception:
>>> failure.test is test
True
>>> failure.example.want
'42\n'
>>> exc_info = failure.exc_info
>>> raise exc_info[0], exc_info[1], exc_info[2]
Traceback (most recent call last):
...
KeyError
If the output doesn't match, then a DocTestFailure is raised:
>>> test = DocTestParser().get_doctest('''
... >>> x = 1
... >>> x
... 2
... ''', {}, 'foo', 'foo.py', 0)
>>> case = DocTestCase(test)
>>> try:
... case.debug()
... except DocTestFailure, failure:
... pass
DocTestFailure objects provide access to the test:
>>> failure.test is test
True
As well as to the example:
>>> failure.example.want
'2\n'
and the actual output:
>>> failure.got
'1\n'
"""
runner = DebugRunner(optionflags=self._dt_optionflags,
checker=self._dt_checker, verbose=False)
runner.run(self._dt_test)
def id(self):
return self._dt_test.name
def __repr__(self):
name = self._dt_test.name.split('.')
return "%s (%s)" % (name[-1], '.'.join(name[:-1]))
__str__ = __repr__
def shortDescription(self):
return "Doctest: " + self._dt_test.name
def DocTestSuite(module=None, globs=None, extraglobs=None,
optionflags=0, test_finder=None,
setUp=lambda: None, tearDown=lambda: None,
checker=None):
"""
Convert doctest tests for a module to a unittest test suite.
This converts each documentation string in a module that
contains doctest tests to a unittest test case. If any of the
tests in a doc string fail, then the test case fails. An exception
is raised showing the name of the file containing the test and a
(sometimes approximate) line number.
The `module` argument provides the module to be tested. The argument
can be either a module or a module name.
If no argument is given, the calling module is used.
"""
if test_finder is None:
test_finder = DocTestFinder()
module = _normalize_module(module)
tests = test_finder.find(module, globs=globs, extraglobs=extraglobs)
if globs is None:
globs = module.__dict__
if not tests: # [XX] why do we want to do this?
raise ValueError(module, "has no tests")
tests.sort()
suite = unittest.TestSuite()
for test in tests:
if len(test.examples) == 0:
continue
if not test.filename:
filename = module.__file__
if filename[-4:] in (".pyc", ".pyo"):
filename = filename[:-1]
test.filename = filename
suite.addTest(DocTestCase(test, optionflags, setUp, tearDown,
checker))
return suite
class DocFileCase(DocTestCase):
def id(self):
return '_'.join(self._dt_test.name.split('.'))
def __repr__(self):
return self._dt_test.filename
__str__ = __repr__
def format_failure(self, err):
return ('Failed doctest test for %s\n File "%s", line 0\n\n%s'
% (self._dt_test.name, self._dt_test.filename, err)
)
def DocFileTest(path, package=None, globs=None,
setUp=None, tearDown=None,
optionflags=0):
package = _normalize_module(package)
name = path.split('/')[-1]
dir = os.path.split(package.__file__)[0]
path = os.path.join(dir, *(path.split('/')))
doc = open(path).read()
if globs is None:
globs = {}
test = DocTestParser().get_doctest(doc, globs, name, path, 0)
return DocFileCase(test, optionflags, setUp, tearDown)
def DocFileSuite(*paths, **kw):
"""Creates a suite of doctest files.
One or more text file paths are given as strings. These should
use "/" characters to separate path segments. Paths are relative
to the directory of the calling module, or relative to the package
passed as a keyword argument.
A number of options may be provided as keyword arguments:
package
The name of a Python package. Text-file paths will be
interpreted relative to the directory containing this package.
The package may be supplied as a package object or as a dotted
package name.
setUp
The name of a set-up function. This is called before running the
tests in each file.
tearDown
The name of a tear-down function. This is called after running the
tests in each file.
globs
A dictionary containing initial global variables for the tests.
"""
suite = unittest.TestSuite()
# We do this here so that _normalize_module is called at the right
# level. If it were called in DocFileTest, then this function
# would be the caller and we might guess the package incorrectly.
kw['package'] = _normalize_module(kw.get('package'))
for path in paths:
suite.addTest(DocFileTest(path, **kw))
return suite
######################################################################
## 9. Debugging Support
######################################################################
def script_from_examples(s):
r"""Extract script from text with examples.
Converts text with examples to a Python script. Example input is
converted to regular code. Example output and all other words
are converted to comments:
>>> text = '''
... Here are examples of simple math.
...
... Python has super accurate integer addition
...
... >>> 2 + 2
... 5
...
... And very friendly error messages:
...
... >>> 1/0
... To Infinity
... And
... Beyond
...
... You can use logic if you want:
...
... >>> if 0:
... ... blah
... ... blah
... ...
...
... Ho hum
... '''
>>> print script_from_examples(text)
# Here are examples of simple math.
#
# Python has super accurate integer addition
#
2 + 2
# Expected:
## 5
#
# And very friendly error messages:
#
1/0
# Expected:
## To Infinity
## And
## Beyond
#
# You can use logic if you want:
#
if 0:
blah
blah
<BLANKLINE>
#
# Ho hum
"""
return DocTestParser().get_program(s)
def _want_comment(example):
"""
Return a comment containing the expected output for the given example.
"""
# Return the expected output, if any
want = example.want
if want:
if want[-1] == '\n':
want = want[:-1]
want = "\n# ".join(want.split("\n"))
want = "\n# Expected:\n# %s" % want
return want
def testsource(module, name):
"""Extract the test sources from a doctest docstring as a script.
Provide the module (or dotted name of the module) containing the
test to be debugged and the name (within the module) of the object
with the doc string with tests to be debugged.
"""
module = _normalize_module(module)
tests = DocTestFinder().find(module)
test = [t for t in tests if t.name == name]
if not test:
raise ValueError(name, "not found in tests")
test = test[0]
testsrc = script_from_examples(test.docstring)
return testsrc
def debug_src(src, pm=False, globs=None):
"""Debug a single doctest docstring, in argument `src`'"""
testsrc = script_from_examples(src)
debug_script(testsrc, pm, globs)
def debug_script(src, pm=False, globs=None):
"Debug a test script. `src` is the script, as a string."
import pdb
# Note that tempfile.NameTemporaryFile() cannot be used. As the
# docs say, a file so created cannot be opened by name a second time
# on modern Windows boxes, and execfile() needs to open it.
srcfilename = tempfile.mktemp(".py", "doctestdebug")
f = open(srcfilename, 'w')
f.write(src)
f.close()
try:
if globs:
globs = globs.copy()
else:
globs = {}
if pm:
try:
execfile(srcfilename, globs, globs)
except:
print sys.exc_info()[1]
pdb.post_mortem(sys.exc_info()[2])
else:
# Note that %r is vital here. '%s' instead can, e.g., cause
# backslashes to get treated as metacharacters on Windows.
pdb.run("execfile(%r)" % srcfilename, globs, globs)
finally:
os.remove(srcfilename)
def debug(module, name, pm=False):
"""Debug a single doctest docstring.
Provide the module (or dotted name of the module) containing the
test to be debugged and the name (within the module) of the object
with the docstring with tests to be debugged.
"""
module = _normalize_module(module)
testsrc = testsource(module, name)
debug_script(testsrc, pm, module.__dict__)
######################################################################
## 10. Example Usage
######################################################################
class _TestClass:
"""
A pointless class, for sanity-checking of docstring testing.
Methods:
square()
get()
>>> _TestClass(13).get() + _TestClass(-12).get()
1
>>> hex(_TestClass(13).square().get())
'0xa9'
"""
def __init__(self, val):
"""val -> _TestClass object with associated value val.
>>> t = _TestClass(123)
>>> print t.get()
123
"""
self.val = val
def square(self):
"""square() -> square TestClass's associated value
>>> _TestClass(13).square().get()
169
"""
self.val = self.val ** 2
return self
def get(self):
"""get() -> return TestClass's associated value.
>>> x = _TestClass(-42)
>>> print x.get()
-42
"""
return self.val
__test__ = {"_TestClass": _TestClass,
"string": r"""
Example of a string object, searched as-is.
>>> x = 1; y = 2
>>> x + y, x * y
(3, 2)
""",
"bool-int equivalence": r"""
In 2.2, boolean expressions displayed
0 or 1. By default, we still accept
them. This can be disabled by passing
DONT_ACCEPT_TRUE_FOR_1 to the new
optionflags argument.
>>> 4 == 4
1
>>> 4 == 4
True
>>> 4 > 4
0
>>> 4 > 4
False
""",
"blank lines": r"""
Blank lines can be marked with <BLANKLINE>:
>>> print 'foo\n\nbar\n'
foo
<BLANKLINE>
bar
<BLANKLINE>
""",
"ellipsis": r"""
If the ellipsis flag is used, then '...' can be used to
elide substrings in the desired output:
>>> print range(1000) #doctest: +ELLIPSIS
[0, 1, 2, ..., 999]
""",
"whitespace normalization": r"""
If the whitespace normalization flag is used, then
differences in whitespace are ignored.
>>> print range(30) #doctest: +NORMALIZE_WHITESPACE
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
27, 28, 29]
""",
}
def _test():
r = unittest.TextTestRunner()
r.run(DocTestSuite())
if __name__ == "__main__":
_test()
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