Skip to main content

better_exchook

A nicer drop-in-replacement for Python sys.excepthook, i.e. it prints stack traces with extended information. It will add some useful information for each frame, like printing the relevant variables (relevant = referenced in the code line). Also see Python source and comments for further details.

Features

  • Shows locals/globals per frame, but only those used in the current statement. It does this by a simple Python code parser.

  • Multi-line Python statements in the stack trace output, in case the statement goes over multiple lines.

  • Shows full function qualified name (not just co_name).

  • Colored/formatted output of each frame.

  • Syntax highlighting for the Python source code.

  • Support for DomTerm text folding (see more), where it folds all the details of each stack frame away by default, and thus provides a much more comprehensive overview, while still providing all the details when needed.

https://github.com/albertz/py_better_exchook/workflows/CI/badge.svg

Installation

You can just copy over the single file better_exchook.py to your project.

Or alternatively, it is also available on PyPI and can be installed via:

pip install better_exchook

Usage

import better_exchook
better_exchook.install()  # will just do: sys.excepthook = better_exchook

Or:

import better_exchook
better_exchook.setup_all()
  • setup_all
    • install + replace_traceback_format_tb + replace_traceback_print_tb

  • install:
    • sys.excepthook = better_exchook

  • replace_traceback_format_tb:
    • traceback.format_tb = format_tb

    • traceback.StackSummary.format = format_tb

    • traceback.StackSummary.extract = _StackSummary_extract

  • replace_traceback_print_tb:
    • traceback.print_tb = print_tb

    • traceback.print_exception = print_exception

    • traceback.print_exc = print_exc

Examples

Python example code:

try:
    x = {1:2, "a":"b"}
    def f():
        y = "foo"
        x, 42, sys.stdin.__class__, sys.exc_info, y, z
    f()
except Exception:
    better_exchook.better_exchook(*sys.exc_info())

Output:

EXCEPTION
Traceback (most recent call last):
  File "better_exchook.py", line 478, in <module>
    line: f()
    locals:
      f = <local> <function f at 0x107f1de60>
  File "better_exchook.py", line 477, in f
    line: x, 42, sys.stdin.__class__, sys.exc_info, y, z
    locals:
      x = <global> {'a': 'b', 1: 2}
      sys = <global> <module 'sys' (built-in)>
      sys.stdin = <global> <open file '<stdin>', mode 'r' at 0x107d9f0c0>
      sys.stdin.__class__ = <global> <type 'file'>
      sys.exc_info = <global> <built-in function exc_info>
      y = <local> 'foo'
      z = <not found>
NameError: global name 'z' is not defined

Python example code:

try:
    f = lambda x: None
    f(x, y)
except Exception:
    better_exchook.better_exchook(*sys.exc_info())

Output:

EXCEPTION
Traceback (most recent call last):
  File "better_exchook.py", line 484, in <module>
    line: f(x, y)
    locals:
      f = <local> <function <lambda> at 0x107f1df50>
      x = <local> {'a': 'b', 1: 2}
      y = <not found>
NameError: name 'y' is not defined

Python example code:

try:
    (lambda x: None)(__name__,
                     42)  # multiline
except Exception:
    better_exchook.better_exchook(*sys.exc_info())

Output:

EXCEPTION
Traceback (most recent call last):
  File "better_exchook.py", line 490, in <module>
    line: (lambda x: None)(__name__,
                           42)  # multiline
    locals:
      x = <local> {'a': 'b', 1: 2}
      __name__ = <local> '__main__', len = 8
TypeError: <lambda>() takes exactly 1 argument (2 given)

Python example code:

# use this to overwrite the global exception handler
sys.excepthook = better_exchook.better_exchook
# and fail
finalfail(sys)

Output:

EXCEPTION
Traceback (most recent call last):
  File "better_exchook.py", line 497, in <module>
    line: finalfail(sys)
    locals:
      finalfail = <not found>
      sys = <local> <module 'sys' (built-in)>
NameError: name 'finalfail' is not defined

Screenshot:

https://gist.githubusercontent.com/albertz/a4ce78e5ccd037041638777f10b10327/raw/7ec2bb7079dbd56119d498f20905404cb2d812c0/screenshot1.png

Screencast with DomTerm using text folding (see more):

https://gist.githubusercontent.com/albertz/a4ce78e5ccd037041638777f10b10327/raw/7ec2bb7079dbd56119d498f20905404cb2d812c0/screencast-domterm.gif

Similar projects

– Albert Zeyer, <http://www.az2000.de>

Metadata

Release files for better-exchook 1.20250617.190044

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for better-exchook 1.20250617.190044
File Size Uploaded Provenance
better_exchook-1.20250617.190044.tar.gz 26.4 kB Without provenance Details

Built distribution (wheel)

Table of built distributions (wheels) for better-exchook 1.20250617.190044
File Interpreter ABI Platform
better_exchook-1.20250617.190044-py3-none-any.whl Python 3 none any Details

Total release size: 52.1 kB

Release files / better_exchook-1.20250617.190044.tar.gz

Download URL better_exchook-1.20250617.190044.tar.gz
Size 26.4 kB
Tags Source
SHA-256 checksum
How to use checksums
d47132c575709607706389f2f87ceeeaccd62795767d8e3f22269ecd7b3a81a1
BLAKE2b-256 checksum
How to use checksums
2bc714bd96cb98728c4831ce48dc7eb7af4771379bfb20d5429e86b02aaa786c
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Release files / better_exchook-1.20250617.190044-py3-none-any.whl

Download URL better_exchook-1.20250617.190044-py3-none-any.whl
Size 25.7 kB
Tags Python 3
SHA-256 checksum
How to use checksums
eb58cfe43d7bb43d2d94133a99ea6ec8e5d4a07252f93a8aa6d89e9a076c1e04
BLAKE2b-256 checksum
How to use checksums
3ed7d20cc22755e97ee4686014e13ec29749a5b10dd19f46a067a78a0300db31
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via twine/6.1.0 CPython/3.9.23

Security for better-exchook 1.20250617.190044

Provenance

Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.

No provenance found

None of the files in this release were uploaded with provenance metadata.

A note on package security

PyPI is a repository for distributing packages, not a service for auditing them. While third-party security researchers and our staff do their best to detect and remove malicious packages, PyPI cannot guarantee the quality, security or suitability of any given package.

To learn more about protecting yourself from malicious actors, visit our package security documentation.

Release history Release notifications | RSS feed

This release

1.20160612.132345

Anthropic, PBC Visionary sponsor Bloomberg Visionary sponsor Hudson River Trading Visionary sponsor Meta Visionary sponsor NVIDIA Visionary sponsor Microsoft Sustainability sponsor Depot Continuous Integration AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page