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Recommend the use of double underscore throwaway variables
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+11
-7
@@ -236,20 +236,24 @@ Create an ignored variable
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~~~~~~~~~~~~~~~~~~~~~~~~~~
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If you need to assign something (for instance, in :ref:`unpacking-ref`) but
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will not need that variable, use ``_``:
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will not need that variable, use ``__``:
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.. code-block:: python
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filename = 'foobar.txt'
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basename, _, ext = filename.rpartition()
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basename, __, ext = filename.rpartition()
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.. note::
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"``_``" is commonly used as an alias for the :func:`~gettext.gettext`
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function. If your application uses (or may someday use) :mod:`gettext`,
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you may want to avoid using ``_`` for ignored variables, as you may
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accidentally shadow :func:`~gettext.gettext`.
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Many Python style guides recommend the use of a single underscore "``_``"
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for throwaway variables rather than the double underscore "``__``"
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recommended here. The issue is that "``_``" is commonly used as an alias
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for the :func:`~gettext.gettext` function, and is also used at the
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interactive prompt to hold the value of the last operation. Using a
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double underscore instead is just as clear and almost as convenient,
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and eliminates the risk of accidentally interfering with either of
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these other use cases.
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Create a length-N list of the same thing
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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