* gh-93883: elide traceback indicators when possible
Elide traceback column indicators when the entire line of the
frame is implicated. This reduces traceback length and draws
even more attention to the remaining (very relevant) indicators.
Example:
```
Traceback (most recent call last):
File "query.py", line 99, in <module>
bar()
File "query.py", line 66, in bar
foo()
File "query.py", line 37, in foo
magic_arithmetic('foo')
File "query.py", line 18, in magic_arithmetic
return add_counts(x) / 25
^^^^^^^^^^^^^
File "query.py", line 24, in add_counts
return 25 + query_user(user1) + query_user(user2)
^^^^^^^^^^^^^^^^^
File "query.py", line 32, in query_user
return 1 + query_count(db, response['a']['b']['c']['user'], retry=True)
~~~~~~~~~~~~~~~~~~^^^^^
TypeError: 'NoneType' object is not subscriptable
```
Rather than going out of our way to provide indicator coverage
in every traceback test suite, the indicator test suite should
be responible for sufficient coverage (e.g. by adding a basic
exception group test to ensure that margin strings are covered).
This is basically something that I noticed up while fixing test runs for another issue. It is really common to have multiline calls, and when they fail the display is kind of weird since we omit the annotations. E.g;
```
$ ./python t.py
Traceback (most recent call last):
File "/home/isidentical/cpython/cpython/t.py", line 11, in <module>
frame_1()
^^^^^^^^^
File "/home/isidentical/cpython/cpython/t.py", line 5, in frame_1
frame_2(
File "/home/isidentical/cpython/cpython/t.py", line 2, in frame_2
return a / 0 / b / c
~~^~~
ZeroDivisionError: division by zero
```
This patch basically adds support for annotating the rest of the line, if the instruction covers multiple lines (start_line != end_line).
Automerge-Triggered-By: GH:isidentical
The traceback.c and traceback.py mechanisms now utilize the newly added code.co_positions and PyCode_Addr2Location
to print carets on the specific expressions involved in a traceback.
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
Co-authored-by: Ammar Askar <ammar@ammaraskar.com>
Co-authored-by: Batuhan Taskaya <batuhanosmantaskaya@gmail.com>
The format_exception(), format_exception_only(), and
print_exception() functions can now take an exception object as a positional-only argument.
Co-Authored-By: Matthias Bussonnier <bussonniermatthias@gmail.com>
This fixes both the traceback.py module and the C code for formatting syntax errors (in Python/pythonrun.c). They now both consistently do the following:
- Suppress caret if it points left of text
- Allow caret pointing just past end of line
- If caret points past end of line, clip to *just* past end of line
The syntax error formatting code in traceback.py was mostly rewritten; small, subtle changes were applied to the C code in pythonrun.c.
There's still a difference when the text contains embedded newlines. Neither handles these very well, and I don't think the case occurs in practice.
Automerge-Triggered-By: @gvanrossum
The recursive frame pruning code always undercounted the number of elided frames
by one. That is, in the "[Previous line repeated N more times]" message, N would
always be one too few. Near the recursive pruning cutoff, one frame could be
silently dropped. That situation is demonstrated in the OP of the bug report.
The fix is to start the identical frame counter at 1.
In the documentation for the traceback module, the definitions of functions
extract_tb(), format_list() and classmethod StackSummary.from_list()
mention the old style 4-tuples that these functions used to return or accept.
Since Python 3.5, however, they return or accept a FrameSummary object
instead of a 4-tuple, or a StackSummary object instead of a list of 4-tuples.
Co-Authored-By: Berker Peksag <berker.peksag@gmail.com>
This fixes a regression caused by revision 73afda5a4e4c. Also reverts the
decimal test workaround added in revision 5f3dd0a2b1ab.
Remove test_without_exception(). According to revision ecaafc32c500, this was
added in Python 2 so that print_exc() would output “None” when called with no
exception set. However print_exc() never worked like this in Python 3, and
the use case is not documented.
Restore TracebackCases class name (instead of SyntaxTracebackCases), because
the class also tests other exceptions.
Large sections of repeated lines in tracebacks are now abbreviated as
"[Previous line repeated {count} more times]" by both the traceback
module and the builtin traceback rendering.
Patch by Emanuel Barry.
