Rich Exception

Python developers use print(variable_foobar) or debugging feature of IDE such as VS Code to troubleshoot, but aren’t there any quicker alternative ways?

rich package can make the exception traceback nicer; show the local variable values and extra lines of code.

How to use

1. Install rich

pip <span>install</span> <span>-U</span> rich
pip <span>install</span> <span>-U</span> rich
pip install -U rich

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1. Place the following code in the beginning of your main module.

<span>try</span><span>:</span>
    <span>from</span> <span>rich.traceback</span> <span>import</span> <span>install</span>
    <span>install</span><span>(</span>
        <span>console</span><span>=</span><span>None</span><span>,</span>
        <span>width</span><span>=</span><span>200</span><span>,</span>
        <span>extra_lines</span><span>=</span><span>3</span><span>,</span>
        <span>theme</span><span>=</span><span>None</span><span>,</span>
        <span>word_wrap</span><span>=</span><span>True</span><span>,</span>
        <span>show_locals</span><span>=</span><span>True</span><span>,</span>
        <span>locals_max_length</span><span>=</span><span>10</span><span>,</span>
        <span>locals_max_string</span><span>=</span><span>80</span><span>,</span>
        <span>locals_hide_dunder</span><span>=</span><span>True</span><span>,</span>
        <span>locals_hide_sunder</span><span>=</span><span>None</span><span>,</span>
        <span>indent_guides</span><span>=</span><span>True</span><span>,</span>
        <span>suppress</span><span>=</span><span>(),</span>
        <span>max_frames</span><span>=</span><span>20</span><span>,</span>
    <span>)</span>
<span>except</span> <span>Exception</span><span>:</span>
    <span>print</span><span>(</span><span>"</span><span>Failed to set up rich traceback. Try: pip install -U rich</span><span>"</span><span>)</span>
<span>try</span><span>:</span>
    <span>from</span> <span>rich.traceback</span> <span>import</span> <span>install</span>

    <span>install</span><span>(</span>
        <span>console</span><span>=</span><span>None</span><span>,</span>
        <span>width</span><span>=</span><span>200</span><span>,</span>
        <span>extra_lines</span><span>=</span><span>3</span><span>,</span>
        <span>theme</span><span>=</span><span>None</span><span>,</span>
        <span>word_wrap</span><span>=</span><span>True</span><span>,</span>
        <span>show_locals</span><span>=</span><span>True</span><span>,</span>
        <span>locals_max_length</span><span>=</span><span>10</span><span>,</span>
        <span>locals_max_string</span><span>=</span><span>80</span><span>,</span>
        <span>locals_hide_dunder</span><span>=</span><span>True</span><span>,</span>
        <span>locals_hide_sunder</span><span>=</span><span>None</span><span>,</span>
        <span>indent_guides</span><span>=</span><span>True</span><span>,</span>
        <span>suppress</span><span>=</span><span>(),</span>
        <span>max_frames</span><span>=</span><span>20</span><span>,</span>
    <span>)</span>
<span>except</span> <span>Exception</span><span>:</span>
    <span>print</span><span>(</span><span>"</span><span>Failed to set up rich traceback. Try: pip install -U rich</span><span>"</span><span>)</span>
try:
    from rich.traceback import install

    install(
        console=None,
        width=200,
        extra_lines=3,
        theme=None,
        word_wrap=True,
        show_locals=True,
        locals_max_length=10,
        locals_max_string=80,
        locals_hide_dunder=True,
        locals_hide_sunder=None,
        indent_guides=True,
        suppress=(),
        max_frames=20,
    )
except Exception:
    print("Failed to set up rich traceback. Try: pip install -U rich")

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Alternatively, to apply to all the codes you run, you may place the Python code in sitecustomize.py file in site-packages directory which can be found by running:

python <span>-c</span> <span>"import sys;print(sys.path)"</span>
python <span>-c</span> <span>"import sys;print(sys.path)"</span>
python -c "import sys;print(sys.path)"

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References

Regarding the options, see the documents:

https://rich.readthedocs.io/en/stable/traceback.html#traceback-handler
https://rich.readthedocs.io/en/stable/reference/traceback.html#rich.traceback.install

原文链接：An alternative way to debug your Python code