GitLocker: The Coding Marketplace

Description:

prettytraceback 2024.1021

Pretty Traceback
Human readable stacktraces for Python.
Project/Repo:

Code Quality/CI:

Overview
Pretty Traceback groups together what belongs together, adds coloring and alignment. All of this makes it easier for you to see patterns and filter out the signal from the noise. This tabular format is best viewed in a wide terminal.
In other words, get this 😍

Instead of this 🤮
Traceback (most recent call last):
File "test/test_formatting.py", line 199, in <module>
main()
File "test/test_formatting.py", line 190, in main
run_pingpong()
File "test/test_formatting.py", line 161, in run_pingpong
sched3.run()
File "/home/mbarkhau/miniconda3/envs/pretty-traceback_py38/lib/python3.8/sched.py", line 151, in run
action(*argument, **kwargs)
File "/home/mbarkhau/miniconda3/envs/pretty-traceback_py38/lib/python3.8/sched.py", line 151, in run
action(*argument, **kwargs)
File "/home/mbarkhau/miniconda3/envs/pretty-traceback_py38/lib/python3.8/sched.py", line 151, in run
action(*argument, **kwargs)
File "test/test_formatting.py", line 151, in _ping
_pong(depth + 1)
File "test/test_formatting.py", line 129, in _pong
_ping(depth + 1)
File "test/test_formatting.py", line 136, in _ping
sp.check_output(["command_that", "doesnt", "exist"])
File "/home/mbarkhau/miniconda3/envs/pretty-traceback_py38/lib/python3.8/subprocess.py", line 411, in check_output
return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
File "/home/mbarkhau/miniconda3/envs/pretty-traceback_py38/lib/python3.8/subprocess.py", line 489, in run
with Popen(*popenargs, **kwargs) as process:
File "/home/mbarkhau/miniconda3/envs/pretty-traceback_py38/lib/python3.8/subprocess.py", line 854, in __init__
self._execute_child(args, executable, preexec_fn, close_fds,
File "/home/mbarkhau/miniconda3/envs/pretty-traceback_py38/lib/python3.8/subprocess.py", line 1702, in _execute_child
raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'command_that'

If your terminal is wide enough, the long paths are preserved.

Usage
Add the following to your __main__.py or the equivalent module which is your entry point.
try:
import pretty_traceback
pretty_traceback.install()
except ImportError:
pass # no need to fail because of missing dev dependency

Please do not add this code e.g. to your __init__.py or any other module that your users may import. They may not want you to mess with how their tracebacks are printed.
If you do feel the overwhelming desire to import the pretty_traceback in code that others might import, consider using the envvar argument, which will cause the install function to effectively be a noop unless you set ENABLE_PRETTY_TRACEBACK=1.
try:
import pretty_traceback
pretty_traceback.install(envvar='ENABLE_PRETTY_TRACEBACK')
except ImportError:
pass # no need to fail because of missing dev dependency

Note, that the hook is only installed if the existing hook is the default. Any existing hooks that were installed before the call of pretty_traceback.install will be left in place.
LoggingFormatter
A logging.Formatter subclass is also available (e.g. for integration with flask).
import os
from flask.logging import default_handler

try:
if os.getenv('FLASK_DEBUG') == "1":
import pretty_traceback
default_handler.setFormatter(pretty_traceback.LoggingFormatter())
except ImportError:
pass # no need to fail because of missing dev dependency

More Examples

Alternatives
Pretty Traceback is heavily inspired by the backtrace module by nir0s but there are many others (sorted by github stars):

https://github.com/qix-/better-exceptions
https://github.com/cknd/stackprinter
https://github.com/onelivesleft/PrettyErrors
https://github.com/skorokithakis/tbvaccine
https://github.com/aroberge/friendly-traceback
https://github.com/HallerPatrick/frosch
https://github.com/nir0s/backtrace
https://github.com/staticshock/colored-traceback.py
https://github.com/chillaranand/ptb
https://github.com/laurb9/rich-traceback
https://github.com/willmcgugan/rich#tracebacks

Contributors

Name
role
since
until

Manuel Barkhau (mbarkhau@gmail.com)
author/maintainer
2020-08
-

Changelog for https://github.com/mbarkhau/pretty-traceback
2024.1021

Update: Avoid leading / on relative paths. gh#13

2023.1020

Fix: Prevent errors in non-tty environments gh#9

2023.1019

Update: Append lineno to filename so it can be parsed by editors/IDEs. gh#8

2022.1018

Add final newline to output. See gh#3

2021.1017

Fix highlight in wide mode

2020.1016

Shorten tracebacks for RecursionError

2020.1012

Improve alias selection

2020.1011

Fix github #1: Invalid path handling for ./script.py

2020.1010

Fix gitlab #5: Only show aliases that were actually used.
Fix gitlab #5: Better alignment on narrow terminals.

2020.1009

Fix gitlab #3: Corner case where exception has None as context.
Fix gitlab #2: Improve formatting when line overflows.

2020.1008

Add pretty_traceback.LoggingFormatter

2020.1006

Add wide mode.

2020.1005

Update formatting to work better with recursive calls.
Add tests

2020.1001

Initial release