mirror of https://github.com/Textualize/rich.git
76 lines
2.4 KiB
ReStructuredText
76 lines
2.4 KiB
ReStructuredText
Traceback
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=========
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Rich can render Python tracebacks with syntax highlighting and formatting. Rich tracebacks are easier to read and show more code than standard Python tracebacks.
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To see an example of a Rich traceback, running the following command::
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python -m rich.traceback
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Printing tracebacks
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-------------------
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The :meth:`~rich.console.Console.print_exception` method will print a traceback for the current exception being handled. Here's an example::
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from rich.console import Console
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console = Console()
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try:
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do_something()
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except Exception:
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console.print_exception(show_locals=True)
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The ``show_locals=True`` parameter causes Rich to display the value of local variables for each frame of the traceback.
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See `exception.py <https://github.com/willmcgugan/rich/blob/master/examples/exception.py>`_ for a larger example.
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Traceback handler
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-----------------
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Rich can be installed as the default traceback handler so that all uncaught exceptions will be rendered with highlighting. Here's how::
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from rich.traceback import install
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install(show_locals=True)
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There are a few options to configure the traceback handler, see :func:`~rich.traceback.install` for details.
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Suppressing Frames
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------------------
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If you are working with a framework (click, django etc), you may only be interested in displaying code in your own application. You can exclude frameworks by setting the `suppress` argument on `Traceback`, `install`, and `print_exception`, which may be a iterable of modules or str paths.
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Here's how you would exclude [click](https://click.palletsprojects.com/en/8.0.x/) from Rich exceptions::
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import click
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from rich.traceback import install
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install(suppress=[click])
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Suppressed frames will show the line and file only, without any code.
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Max Frames
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----------
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A recursion error can generate very large tracebacks that take a while to render and contain a lot of repetitive frames. Rich guards against this with a `max_frames` argument, which defaults to 100. If a traceback contains more than 100 frames then only the first 50, and last 50 will be shown. You can disable this feature by setting `max_frames` to 0.
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Here's an example of printing an recursive error::
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from rich.console import Console
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def foo(n):
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return bar(n)
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def bar(n):
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return foo(n)
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console = Console()
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try:
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foo(1)
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except Exception:
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console.print_exception(max_frames=20) |