109 lines
11 KiB
ReStructuredText
109 lines
11 KiB
ReStructuredText
.. _python_37:
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Python 3.7
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==========
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New Features:
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.. table::
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:widths: 20 60 20
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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| **Feature** | **Status** |
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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| `PEP 538 <https://www.python.org/dev/peps/pep-0538/>`_ | Coercing the legacy C locale to a UTF-8 based | |
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| | locale | |
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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| `PEP 539 <https://www.python.org/dev/peps/pep-0539/>`_ | A New C-API for Thread-Local Storage in CPython | |
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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| `PEP 540 <https://www.python.org/dev/peps/pep-0540/>`_ | UTF-8 mode | |
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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| `PEP 552 <https://www.python.org/dev/peps/pep-0552/>`_ | Deterministic pyc | |
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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| `PEP 553 <https://www.python.org/dev/peps/pep-0553/>`_ | Built-in ``breakpoint()`` | |
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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| `PEP 557 <https://www.python.org/dev/peps/pep-0557/>`_ | Data Classes | |
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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| `PEP 560 <https://www.python.org/dev/peps/pep-0560/>`_ | Core support for typing module and generic types | |
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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| `PEP 562 <https://www.python.org/dev/peps/pep-0562/>`_ | Module ``__getattr__`` and ``__dir__`` | Partial |
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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| `PEP 563 <https://www.python.org/dev/peps/pep-0563/>`_ | Postponed Evaluation of Annotations | |
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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| `PEP 564 <https://www.python.org/dev/peps/pep-0564/>`_ | Time functions with nanosecond resolution | Partial [#ftimenanosec]_ |
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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| `PEP 565 <https://www.python.org/dev/peps/pep-0565/>`_ | Show DeprecationWarning in ``__main__`` | |
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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| `PEP 567 <https://www.python.org/dev/peps/pep-0567/>`_ | Context Variables | |
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+--------------------------------------------------------+--------------------------------------------------+--------------------------------------+
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Other Language Changes:
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.. table::
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:widths: 90 10
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+-----------------------------------------------------------------------------------------------------------------+----------------+
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| ``async`` and ``await`` are now reserved keywords | Complete |
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+-----------------------------------------------------------------------------------------------------------------+----------------+
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| ``dict`` objects must preserve insertion-order | |
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+-----------------------------------------------------------------------------------------------------------------+----------------+
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| More than 255 arguments can now be passed to a function; a function can now have more than 255 parameters | |
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+-----------------------------------------------------------------------------------------------------------------+----------------+
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| ``bytes.fromhex()`` and ``bytearray.fromhex()`` now ignore all ASCII whitespace, not only spaces | |
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+-----------------------------------------------------------------------------------------------------------------+----------------+
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| ``str``, ``bytes``, and ``bytearray`` gained support for the new ``isascii()`` method, which can be used to | |
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| test if a string or bytes contain only the ASCII characters | |
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+-----------------------------------------------------------------------------------------------------------------+----------------+
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| ``ImportError`` now displays module name and module ``__file__`` path when ``from ... import ...`` fails | |
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+-----------------------------------------------------------------------------------------------------------------+----------------+
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| Circular imports involving absolute imports with binding a submodule to a name are now supported | |
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+-----------------------------------------------------------------------------------------------------------------+----------------+
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| ``object.__format__(x, '')`` is now equivalent to ``str(x)`` rather than ``format(str(self), '')`` | |
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+-----------------------------------------------------------------------------------------------------------------+----------------+
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| In order to better support dynamic creation of stack traces, ``types.TracebackType`` can now be | |
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| instantiated from Python code, and the ``tb_next`` attribute on tracebacks is now writable | |
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+-----------------------------------------------------------------------------------------------------------------+----------------+
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| When using the ``-m`` switch, ``sys.path[0]`` is now eagerly expanded to the full starting directory path, | |
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| rather than being left as the empty directory (which allows imports from the current working directory | |
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| at the time when an import occurs) | |
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+-----------------------------------------------------------------------------------------------------------------+----------------+
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| The new ``-X importtime`` option or the ``PYTHONPROFILEIMPORTTIME`` environment variable can be used to | |
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| show the timing of each module import | |
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+-----------------------------------------------------------------------------------------------------------------+----------------+
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Changes to built-in modules:
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.. table::
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:widths: 90 10
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+------------------------------------------------------------------------------------------------------------+----------------+
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| `asyncio <https://docs.python.org/3/whatsnew/3.7.html#asyncio>`_ | |
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+------------------------------------------------------------------------------------------------------------+----------------+
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| Too many to list | |
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+------------------------------------------------------------------------------------------------------------+----------------+
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| `gc <https://docs.python.org/3/whatsnew/3.7.html#gc>`_ | |
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+------------------------------------------------------------------------------------------------------------+----------------+
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| New features include *gc.freeze()*, *gc.unfreeze()*, *gc-get_freeze_count* | |
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+------------------------------------------------------------------------------------------------------------+----------------+
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| `math <https://docs.python.org/3/whatsnew/3.7.html#math>`_ | |
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+------------------------------------------------------------------------------------------------------------+----------------+
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| math.remainder() added to implement IEEE 754-style remainder | |
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+------------------------------------------------------------------------------------------------------------+----------------+
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| `re <https://docs.python.org/3/whatsnew/3.7.html#re>`_ | |
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+------------------------------------------------------------------------------------------------------------+----------------+
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| A number of tidy up features including better support for splitting on empty strings and copy support for | |
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| compiled expressions and match objects | |
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+------------------------------------------------------------------------------------------------------------+----------------+
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| `sys <https://docs.python.org/3/whatsnew/3.7.html#sys>`_ | |
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+------------------------------------------------------------------------------------------------------------+----------------+
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| sys.breakpointhook() added. sys.get(/set)_coroutine_origin_tracking_depth() added | |
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+------------------------------------------------------------------------------------------------------------+----------------+
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| `time <https://docs.python.org/3/whatsnew/3.7.html#time>`_ | |
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+------------------------------------------------------------------------------------------------------------+----------------+
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| Mostly updates to support nanosecond resolution in PEP564, see above | |
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+------------------------------------------------------------------------------------------------------------+----------------+
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.. rubric:: Notes
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.. [#ftimenanosec] Only :func:`time.time_ns` is implemented.
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