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61 lines
1.9 KiB
ReStructuredText
61 lines
1.9 KiB
ReStructuredText
:mod:`future_builtins` --- Python 3 builtins
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============================================
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.. module:: future_builtins
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.. sectionauthor:: Georg Brandl
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.. versionadded:: 2.6
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This module provides functions that exist in 2.x, but have different behavior in
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Python 3, so they cannot be put into the 2.x builtin namespace.
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Instead, if you want to write code compatible with Python 3 builtins, import
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them from this module, like this::
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from future_builtins import map, filter
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... code using Python 3-style map and filter ...
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The :term:`2to3` tool that ports Python 2 code to Python 3 will recognize
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this usage and leave the new builtins alone.
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.. note::
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The Python 3 :func:`print` function is already in the builtins, but cannot be
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accessed from Python 2 code unless you use the appropriate future statement::
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from __future__ import print_function
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Available builtins are:
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.. function:: ascii(object)
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Returns the same as :func:`repr`. In Python 3, :func:`repr` will return
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printable Unicode characters unescaped, while :func:`ascii` will always
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backslash-escape them. Using :func:`future_builtins.ascii` instead of
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:func:`repr` in 2.6 code makes it clear that you need a pure ASCII return
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value.
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.. function:: filter(function, iterable)
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Works like :func:`itertools.ifilter`.
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.. function:: hex(object)
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Works like the builtin :func:`hex`, but instead of :meth:`__hex__` it will
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use the :meth:`__index__` method on its argument to get an integer that is
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then converted to hexadecimal.
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.. function:: map(function, iterable, ...)
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Works like :func:`itertools.imap`.
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.. function:: oct(object)
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Works like the builtin :func:`oct`, but instead of :meth:`__oct__` it will
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use the :meth:`__index__` method on its argument to get an integer that is
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then converted to hexadecimal.
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.. function:: zip(*iterables)
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Works like :func:`itertools.izip`.
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