mirror of
https://github.com/python/cpython.git
synced 2024-12-12 03:04:15 +08:00
e65282114e
patch from Antoine Pitrou #3112
338 lines
12 KiB
Python
338 lines
12 KiB
Python
"""Extract, format and print information about Python stack traces."""
|
|
|
|
import linecache
|
|
import sys
|
|
import types
|
|
import itertools
|
|
|
|
__all__ = ['extract_stack', 'extract_tb', 'format_exception',
|
|
'format_exception_only', 'format_list', 'format_stack',
|
|
'format_tb', 'print_exc', 'format_exc', 'print_exception',
|
|
'print_last', 'print_stack', 'print_tb']
|
|
|
|
def _print(file, str='', terminator='\n'):
|
|
file.write(str+terminator)
|
|
|
|
|
|
def print_list(extracted_list, file=None):
|
|
"""Print the list of tuples as returned by extract_tb() or
|
|
extract_stack() as a formatted stack trace to the given file."""
|
|
if file is None:
|
|
file = sys.stderr
|
|
for filename, lineno, name, line in extracted_list:
|
|
_print(file,
|
|
' File "%s", line %d, in %s' % (filename,lineno,name))
|
|
if line:
|
|
_print(file, ' %s' % line.strip())
|
|
|
|
def format_list(extracted_list):
|
|
"""Format a list of traceback entry tuples for printing.
|
|
|
|
Given a list of tuples as returned by extract_tb() or
|
|
extract_stack(), return a list of strings ready for printing.
|
|
Each string in the resulting list corresponds to the item with the
|
|
same index in the argument list. Each string ends in a newline;
|
|
the strings may contain internal newlines as well, for those items
|
|
whose source text line is not None.
|
|
"""
|
|
list = []
|
|
for filename, lineno, name, line in extracted_list:
|
|
item = ' File "%s", line %d, in %s\n' % (filename,lineno,name)
|
|
if line:
|
|
item = item + ' %s\n' % line.strip()
|
|
list.append(item)
|
|
return list
|
|
|
|
|
|
def print_tb(tb, limit=None, file=None):
|
|
"""Print up to 'limit' stack trace entries from the traceback 'tb'.
|
|
|
|
If 'limit' is omitted or None, all entries are printed. If 'file'
|
|
is omitted or None, the output goes to sys.stderr; otherwise
|
|
'file' should be an open file or file-like object with a write()
|
|
method.
|
|
"""
|
|
if file is None:
|
|
file = sys.stderr
|
|
if limit is None:
|
|
if hasattr(sys, 'tracebacklimit'):
|
|
limit = sys.tracebacklimit
|
|
n = 0
|
|
while tb is not None and (limit is None or n < limit):
|
|
f = tb.tb_frame
|
|
lineno = tb.tb_lineno
|
|
co = f.f_code
|
|
filename = co.co_filename
|
|
name = co.co_name
|
|
_print(file,
|
|
' File "%s", line %d, in %s' % (filename,lineno,name))
|
|
linecache.checkcache(filename)
|
|
line = linecache.getline(filename, lineno, f.f_globals)
|
|
if line: _print(file, ' ' + line.strip())
|
|
tb = tb.tb_next
|
|
n = n+1
|
|
|
|
def format_tb(tb, limit = None):
|
|
"""A shorthand for 'format_list(extract_stack(f, limit))."""
|
|
return format_list(extract_tb(tb, limit))
|
|
|
|
def extract_tb(tb, limit = None):
|
|
"""Return list of up to limit pre-processed entries from traceback.
|
|
|
|
This is useful for alternate formatting of stack traces. If
|
|
'limit' is omitted or None, all entries are extracted. A
|
|
pre-processed stack trace entry is a quadruple (filename, line
|
|
number, function name, text) representing the information that is
|
|
usually printed for a stack trace. The text is a string with
|
|
leading and trailing whitespace stripped; if the source is not
|
|
available it is None.
|
|
"""
|
|
if limit is None:
|
|
if hasattr(sys, 'tracebacklimit'):
|
|
limit = sys.tracebacklimit
|
|
list = []
|
|
n = 0
|
|
while tb is not None and (limit is None or n < limit):
|
|
f = tb.tb_frame
|
|
lineno = tb.tb_lineno
|
|
co = f.f_code
|
|
filename = co.co_filename
|
|
name = co.co_name
|
|
linecache.checkcache(filename)
|
|
line = linecache.getline(filename, lineno, f.f_globals)
|
|
if line: line = line.strip()
|
|
else: line = None
|
|
list.append((filename, lineno, name, line))
|
|
tb = tb.tb_next
|
|
n = n+1
|
|
return list
|
|
|
|
|
|
_cause_message = (
|
|
"\nThe above exception was the direct cause "
|
|
"of the following exception:\n")
|
|
|
|
_context_message = (
|
|
"\nDuring handling of the above exception, "
|
|
"another exception occurred:\n")
|
|
|
|
def _iter_chain(exc, custom_tb=None, seen=None):
|
|
if seen is None:
|
|
seen = set()
|
|
seen.add(exc)
|
|
its = []
|
|
cause = exc.__cause__
|
|
context = exc.__context__
|
|
if cause is not None and cause not in seen:
|
|
its.append(_iter_chain(cause, None, seen))
|
|
its.append([(_cause_message, None)])
|
|
if context is not None and context is not cause and context not in seen:
|
|
its.append(_iter_chain(context, None, seen))
|
|
its.append([(_context_message, None)])
|
|
its.append([(exc, custom_tb or exc.__traceback__)])
|
|
return itertools.chain(*its)
|
|
|
|
|
|
def print_exception(etype, value, tb, limit=None, file=None, chain=True):
|
|
"""Print exception up to 'limit' stack trace entries from 'tb' to 'file'.
|
|
|
|
This differs from print_tb() in the following ways: (1) if
|
|
traceback is not None, it prints a header "Traceback (most recent
|
|
call last):"; (2) it prints the exception type and value after the
|
|
stack trace; (3) if type is SyntaxError and value has the
|
|
appropriate format, it prints the line where the syntax error
|
|
occurred with a caret on the next line indicating the approximate
|
|
position of the error.
|
|
"""
|
|
if file is None:
|
|
file = sys.stderr
|
|
if chain:
|
|
values = _iter_chain(value, tb)
|
|
else:
|
|
values = [(value, tb)]
|
|
for value, tb in values:
|
|
if isinstance(value, str):
|
|
_print(file, value)
|
|
continue
|
|
if tb:
|
|
_print(file, 'Traceback (most recent call last):')
|
|
print_tb(tb, limit, file)
|
|
lines = format_exception_only(type(value), value)
|
|
for line in lines[:-1]:
|
|
_print(file, line, ' ')
|
|
_print(file, lines[-1], '')
|
|
|
|
def format_exception(etype, value, tb, limit=None, chain=True):
|
|
"""Format a stack trace and the exception information.
|
|
|
|
The arguments have the same meaning as the corresponding arguments
|
|
to print_exception(). The return value is a list of strings, each
|
|
ending in a newline and some containing internal newlines. When
|
|
these lines are concatenated and printed, exactly the same text is
|
|
printed as does print_exception().
|
|
"""
|
|
list = []
|
|
if chain:
|
|
values = _iter_chain(value, tb)
|
|
else:
|
|
values = [(value, tb)]
|
|
for value, tb in values:
|
|
if isinstance(value, str):
|
|
list.append(value + '\n')
|
|
continue
|
|
if tb:
|
|
list.append('Traceback (most recent call last):\n')
|
|
list.extend(format_tb(tb, limit))
|
|
list.extend(format_exception_only(type(value), value))
|
|
return list
|
|
|
|
def format_exception_only(etype, value):
|
|
"""Format the exception part of a traceback.
|
|
|
|
The arguments are the exception type and value such as given by
|
|
sys.last_type and sys.last_value. The return value is a list of
|
|
strings, each ending in a newline.
|
|
|
|
Normally, the list contains a single string; however, for
|
|
SyntaxError exceptions, it contains several lines that (when
|
|
printed) display detailed information about where the syntax
|
|
error occurred.
|
|
|
|
The message indicating which exception occurred is always the last
|
|
string in the list.
|
|
|
|
"""
|
|
# Gracefully handle (the way Python 2.4 and earlier did) the case of
|
|
# being called with (None, None).
|
|
if etype is None:
|
|
return [_format_final_exc_line(etype, value)]
|
|
|
|
stype = etype.__name__
|
|
smod = etype.__module__
|
|
if smod not in ("__main__", "builtins"):
|
|
stype = smod + '.' + stype
|
|
|
|
if not issubclass(etype, SyntaxError):
|
|
return [_format_final_exc_line(stype, value)]
|
|
|
|
# It was a syntax error; show exactly where the problem was found.
|
|
lines = []
|
|
filename = value.filename or "<string>"
|
|
lineno = str(value.lineno) or '?'
|
|
lines.append(' File "%s", line %s\n' % (filename, lineno))
|
|
badline = value.text
|
|
offset = value.offset
|
|
if badline is not None:
|
|
lines.append(' %s\n' % badline.strip())
|
|
if offset is not None:
|
|
caretspace = badline[:offset].lstrip()
|
|
# non-space whitespace (likes tabs) must be kept for alignment
|
|
caretspace = ((c.isspace() and c or ' ') for c in caretspace)
|
|
# only three spaces to account for offset1 == pos 0
|
|
lines.append(' %s^\n' % ''.join(caretspace))
|
|
msg = value.msg or "<no detail available>"
|
|
lines.append("%s: %s\n" % (stype, msg))
|
|
return lines
|
|
|
|
def _format_final_exc_line(etype, value):
|
|
valuestr = _some_str(value)
|
|
if value is None or not valuestr:
|
|
line = "%s\n" % etype
|
|
else:
|
|
line = "%s: %s\n" % (etype, valuestr)
|
|
return line
|
|
|
|
def _some_str(value):
|
|
try:
|
|
return str(value)
|
|
except:
|
|
return '<unprintable %s object>' % type(value).__name__
|
|
|
|
|
|
def print_exc(limit=None, file=None, chain=True):
|
|
"""Shorthand for 'print_exception(*sys.exc_info(), limit, file)'."""
|
|
if file is None:
|
|
file = sys.stderr
|
|
try:
|
|
etype, value, tb = sys.exc_info()
|
|
print_exception(etype, value, tb, limit, file, chain)
|
|
finally:
|
|
etype = value = tb = None
|
|
|
|
|
|
def format_exc(limit=None, chain=True):
|
|
"""Like print_exc() but return a string."""
|
|
try:
|
|
etype, value, tb = sys.exc_info()
|
|
return ''.join(
|
|
format_exception(etype, value, tb, limit, chain))
|
|
finally:
|
|
etype = value = tb = None
|
|
|
|
|
|
def print_last(limit=None, file=None, chain=True):
|
|
"""This is a shorthand for 'print_exception(sys.last_type,
|
|
sys.last_value, sys.last_traceback, limit, file)'."""
|
|
if file is None:
|
|
file = sys.stderr
|
|
print_exception(sys.last_type, sys.last_value, sys.last_traceback,
|
|
limit, file, chain)
|
|
|
|
|
|
def print_stack(f=None, limit=None, file=None):
|
|
"""Print a stack trace from its invocation point.
|
|
|
|
The optional 'f' argument can be used to specify an alternate
|
|
stack frame at which to start. The optional 'limit' and 'file'
|
|
arguments have the same meaning as for print_exception().
|
|
"""
|
|
if f is None:
|
|
try:
|
|
raise ZeroDivisionError
|
|
except ZeroDivisionError:
|
|
f = sys.exc_info()[2].tb_frame.f_back
|
|
print_list(extract_stack(f, limit), file)
|
|
|
|
def format_stack(f=None, limit=None):
|
|
"""Shorthand for 'format_list(extract_stack(f, limit))'."""
|
|
if f is None:
|
|
try:
|
|
raise ZeroDivisionError
|
|
except ZeroDivisionError:
|
|
f = sys.exc_info()[2].tb_frame.f_back
|
|
return format_list(extract_stack(f, limit))
|
|
|
|
def extract_stack(f=None, limit = None):
|
|
"""Extract the raw traceback from the current stack frame.
|
|
|
|
The return value has the same format as for extract_tb(). The
|
|
optional 'f' and 'limit' arguments have the same meaning as for
|
|
print_stack(). Each item in the list is a quadruple (filename,
|
|
line number, function name, text), and the entries are in order
|
|
from oldest to newest stack frame.
|
|
"""
|
|
if f is None:
|
|
try:
|
|
raise ZeroDivisionError
|
|
except ZeroDivisionError:
|
|
f = sys.exc_info()[2].tb_frame.f_back
|
|
if limit is None:
|
|
if hasattr(sys, 'tracebacklimit'):
|
|
limit = sys.tracebacklimit
|
|
list = []
|
|
n = 0
|
|
while f is not None and (limit is None or n < limit):
|
|
lineno = f.f_lineno
|
|
co = f.f_code
|
|
filename = co.co_filename
|
|
name = co.co_name
|
|
linecache.checkcache(filename)
|
|
line = linecache.getline(filename, lineno, f.f_globals)
|
|
if line: line = line.strip()
|
|
else: line = None
|
|
list.append((filename, lineno, name, line))
|
|
f = f.f_back
|
|
n = n+1
|
|
list.reverse()
|
|
return list
|