|
| 1 | +This is Python version 3.8.0 alpha 0 |
| 2 | +==================================== |
| 3 | + |
| 4 | +.. image:: https://travis-ci.org/python/cpython.svg?branch=master |
| 5 | + :alt: CPython build status on Travis CI |
| 6 | + :target: https://travis-ci.org/python/cpython |
| 7 | + |
| 8 | +.. image:: https://ci.appveyor.com/api/projects/status/4mew1a93xdkbf5ua/branch/master?svg=true |
| 9 | + :alt: CPython build status on Appveyor |
| 10 | + :target: https://ci.appveyor.com/project/python/cpython/branch/master |
| 11 | + |
| 12 | +.. image:: https://dev.azure.com/python/cpython/_apis/build/status/Azure%20Pipelines%20CI?branchName=master |
| 13 | + :alt: CPython build status on Azure DevOps |
| 14 | + :target: https://dev.azure.com/python/cpython/_build/latest?definitionId=4&branchName=master |
| 15 | + |
| 16 | +.. image:: https://codecov.io/gh/python/cpython/branch/master/graph/badge.svg |
| 17 | + :alt: CPython code coverage on Codecov |
| 18 | + :target: https://codecov.io/gh/python/cpython |
| 19 | + |
| 20 | +.. image:: https://img.shields.io/badge/zulip-join_chat-brightgreen.svg |
| 21 | + :alt: Python Zulip chat |
| 22 | + :target: https://python.zulipchat.com |
| 23 | + |
| 24 | + |
| 25 | +Copyright (c) 2001-2019 Python Software Foundation. All rights reserved. |
| 26 | + |
| 27 | +See the end of this file for further copyright and license information. |
| 28 | + |
| 29 | +.. contents:: |
| 30 | + |
| 31 | +General Information |
| 32 | +------------------- |
| 33 | + |
| 34 | +- Website: https://www.python.org |
| 35 | +- Source code: https://github.com/python/cpython |
| 36 | +- Issue tracker: https://bugs.python.org |
| 37 | +- Documentation: https://docs.python.org |
| 38 | +- Developer's Guide: https://devguide.python.org/ |
| 39 | + |
| 40 | +Contributing to CPython |
| 41 | +----------------------- |
| 42 | + |
| 43 | +For more complete instructions on contributing to CPython development, |
| 44 | +see the `Developer Guide`_. |
| 45 | + |
| 46 | +.. _Developer Guide: https://devguide.python.org/ |
| 47 | + |
| 48 | +Using Python |
| 49 | +------------ |
| 50 | + |
| 51 | +Installable Python kits, and information about using Python, are available at |
| 52 | +`python.org`_. |
| 53 | + |
| 54 | +.. _python.org: https://www.python.org/ |
| 55 | + |
| 56 | +Build Instructions |
| 57 | +------------------ |
| 58 | + |
| 59 | +On Unix, Linux, BSD, macOS, and Cygwin:: |
| 60 | + |
| 61 | + ./configure |
| 62 | + make |
| 63 | + make test |
| 64 | + sudo make install |
| 65 | + |
| 66 | +This will install Python as ``python3``. |
| 67 | + |
| 68 | +You can pass many options to the configure script; run ``./configure --help`` |
| 69 | +to find out more. On macOS and Cygwin, the executable is called ``python.exe``; |
| 70 | +elsewhere it's just ``python``. |
| 71 | + |
| 72 | +If you are running on macOS with the latest updates installed, make sure to install |
| 73 | +openSSL or some other SSL software along with Homebrew or another package manager. |
| 74 | +If issues persist, see https://devguide.python.org/setup/#macos-and-os-x for more |
| 75 | +information. |
| 76 | + |
| 77 | +On macOS, if you have configured Python with ``--enable-framework``, you |
| 78 | +should use ``make frameworkinstall`` to do the installation. Note that this |
| 79 | +installs the Python executable in a place that is not normally on your PATH, |
| 80 | +you may want to set up a symlink in ``/usr/local/bin``. |
| 81 | + |
| 82 | +On Windows, see `PCbuild/readme.txt |
| 83 | +<https://github.com/python/cpython/blob/master/PCbuild/readme.txt>`_. |
| 84 | + |
| 85 | +If you wish, you can create a subdirectory and invoke configure from there. |
| 86 | +For example:: |
| 87 | + |
| 88 | + mkdir debug |
| 89 | + cd debug |
| 90 | + ../configure --with-pydebug |
| 91 | + make |
| 92 | + make test |
| 93 | + |
| 94 | +(This will fail if you *also* built at the top-level directory. You should do |
| 95 | +a ``make clean`` at the toplevel first.) |
| 96 | + |
| 97 | +To get an optimized build of Python, ``configure --enable-optimizations`` |
| 98 | +before you run ``make``. This sets the default make targets up to enable |
| 99 | +Profile Guided Optimization (PGO) and may be used to auto-enable Link Time |
| 100 | +Optimization (LTO) on some platforms. For more details, see the sections |
| 101 | +below. |
| 102 | + |
| 103 | + |
| 104 | +Profile Guided Optimization |
| 105 | +^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
| 106 | + |
| 107 | +PGO takes advantage of recent versions of the GCC or Clang compilers. If used, |
| 108 | +either via ``configure --enable-optimizations`` or by manually running |
| 109 | +``make profile-opt`` regardless of configure flags, the optimized build |
| 110 | +process will perform the following steps: |
| 111 | + |
| 112 | +The entire Python directory is cleaned of temporary files that may have |
| 113 | +resulted from a previous compilation. |
| 114 | + |
| 115 | +An instrumented version of the interpreter is built, using suitable compiler |
| 116 | +flags for each flavour. Note that this is just an intermediary step. The |
| 117 | +binary resulting from this step is not good for real life workloads as it has |
| 118 | +profiling instructions embedded inside. |
| 119 | + |
| 120 | +After the instrumented interpreter is built, the Makefile will run a training |
| 121 | +workload. This is necessary in order to profile the interpreter execution. |
| 122 | +Note also that any output, both stdout and stderr, that may appear at this step |
| 123 | +is suppressed. |
| 124 | + |
| 125 | +The final step is to build the actual interpreter, using the information |
| 126 | +collected from the instrumented one. The end result will be a Python binary |
| 127 | +that is optimized; suitable for distribution or production installation. |
| 128 | + |
| 129 | + |
| 130 | +Link Time Optimization |
| 131 | +^^^^^^^^^^^^^^^^^^^^^^ |
| 132 | + |
| 133 | +Enabled via configure's ``--with-lto`` flag. LTO takes advantage of the |
| 134 | +ability of recent compiler toolchains to optimize across the otherwise |
| 135 | +arbitrary ``.o`` file boundary when building final executables or shared |
| 136 | +libraries for additional performance gains. |
| 137 | + |
| 138 | + |
| 139 | +What's New |
| 140 | +---------- |
| 141 | + |
| 142 | +We have a comprehensive overview of the changes in the `What's New in Python |
| 143 | +3.8 <https://docs.python.org/3.8/whatsnew/3.8.html>`_ document. For a more |
| 144 | +detailed change log, read `Misc/NEWS |
| 145 | +<https://github.com/python/cpython/blob/master/Misc/NEWS.d>`_, but a full |
| 146 | +accounting of changes can only be gleaned from the `commit history |
| 147 | +<https://github.com/python/cpython/commits/master>`_. |
| 148 | + |
| 149 | +If you want to install multiple versions of Python see the section below |
| 150 | +entitled "Installing multiple versions". |
| 151 | + |
| 152 | + |
| 153 | +Documentation |
| 154 | +------------- |
| 155 | + |
| 156 | +`Documentation for Python 3.8 <https://docs.python.org/3.8/>`_ is online, |
| 157 | +updated daily. |
| 158 | + |
| 159 | +It can also be downloaded in many formats for faster access. The documentation |
| 160 | +is downloadable in HTML, PDF, and reStructuredText formats; the latter version |
| 161 | +is primarily for documentation authors, translators, and people with special |
| 162 | +formatting requirements. |
| 163 | + |
| 164 | +For information about building Python's documentation, refer to `Doc/README.rst |
| 165 | +<https://github.com/python/cpython/blob/master/Doc/README.rst>`_. |
| 166 | + |
| 167 | + |
| 168 | +Converting From Python 2.x to 3.x |
| 169 | +--------------------------------- |
| 170 | + |
| 171 | +Significant backward incompatible changes were made for the release of Python |
| 172 | +3.0, which may cause programs written for Python 2 to fail when run with Python |
| 173 | +3. For more information about porting your code from Python 2 to Python 3, see |
| 174 | +the `Porting HOWTO <https://docs.python.org/3/howto/pyporting.html>`_. |
| 175 | + |
| 176 | + |
| 177 | +Testing |
| 178 | +------- |
| 179 | + |
| 180 | +To test the interpreter, type ``make test`` in the top-level directory. The |
| 181 | +test set produces some output. You can generally ignore the messages about |
| 182 | +skipped tests due to optional features which can't be imported. If a message |
| 183 | +is printed about a failed test or a traceback or core dump is produced, |
| 184 | +something is wrong. |
| 185 | + |
| 186 | +By default, tests are prevented from overusing resources like disk space and |
| 187 | +memory. To enable these tests, run ``make testall``. |
| 188 | + |
| 189 | +If any tests fail, you can re-run the failing test(s) in verbose mode. For |
| 190 | +example, if ``test_os`` and ``test_gdb`` failed, you can run:: |
| 191 | + |
| 192 | + make test TESTOPTS="-v test_os test_gdb" |
| 193 | + |
| 194 | +If the failure persists and appears to be a problem with Python rather than |
| 195 | +your environment, you can `file a bug report <https://bugs.python.org>`_ and |
| 196 | +include relevant output from that command to show the issue. |
| 197 | + |
| 198 | +See `Running & Writing Tests <https://devguide.python.org/runtests/>`_ |
| 199 | +for more on running tests. |
| 200 | + |
| 201 | +Installing multiple versions |
| 202 | +---------------------------- |
| 203 | + |
| 204 | +On Unix and Mac systems if you intend to install multiple versions of Python |
| 205 | +using the same installation prefix (``--prefix`` argument to the configure |
| 206 | +script) you must take care that your primary python executable is not |
| 207 | +overwritten by the installation of a different version. All files and |
| 208 | +directories installed using ``make altinstall`` contain the major and minor |
| 209 | +version and can thus live side-by-side. ``make install`` also creates |
| 210 | +``${prefix}/bin/python3`` which refers to ``${prefix}/bin/pythonX.Y``. If you |
| 211 | +intend to install multiple versions using the same prefix you must decide which |
| 212 | +version (if any) is your "primary" version. Install that version using ``make |
| 213 | +install``. Install all other versions using ``make altinstall``. |
| 214 | + |
| 215 | +For example, if you want to install Python 2.7, 3.6, and 3.8 with 3.8 being the |
| 216 | +primary version, you would execute ``make install`` in your 3.8 build directory |
| 217 | +and ``make altinstall`` in the others. |
| 218 | + |
| 219 | + |
| 220 | +Issue Tracker and Mailing List |
| 221 | +------------------------------ |
| 222 | + |
| 223 | +Bug reports are welcome! You can use the `issue tracker |
| 224 | +<https://bugs.python.org>`_ to report bugs, and/or submit pull requests `on |
| 225 | +GitHub <https://github.com/python/cpython>`_. |
| 226 | + |
| 227 | +You can also follow development discussion on the `python-dev mailing list |
| 228 | +<https://mail.python.org/mailman/listinfo/python-dev/>`_. |
| 229 | + |
| 230 | + |
| 231 | +Proposals for enhancement |
| 232 | +------------------------- |
| 233 | + |
| 234 | +If you have a proposal to change Python, you may want to send an email to the |
| 235 | +comp.lang.python or `python-ideas`_ mailing lists for initial feedback. A |
| 236 | +Python Enhancement Proposal (PEP) may be submitted if your idea gains ground. |
| 237 | +All current PEPs, as well as guidelines for submitting a new PEP, are listed at |
| 238 | +`python.org/dev/peps/ <https://www.python.org/dev/peps/>`_. |
| 239 | + |
| 240 | +.. _python-ideas: https://mail.python.org/mailman/listinfo/python-ideas/ |
| 241 | + |
| 242 | + |
| 243 | +Release Schedule |
| 244 | +---------------- |
| 245 | + |
| 246 | +See :pep:`569` for Python 3.8 release details. |
| 247 | + |
| 248 | + |
| 249 | +Copyright and License Information |
| 250 | +--------------------------------- |
| 251 | + |
| 252 | +Copyright (c) 2001-2019 Python Software Foundation. All rights reserved. |
| 253 | + |
| 254 | +Copyright (c) 2000 BeOpen.com. All rights reserved. |
| 255 | + |
| 256 | +Copyright (c) 1995-2001 Corporation for National Research Initiatives. All |
| 257 | +rights reserved. |
| 258 | + |
| 259 | +Copyright (c) 1991-1995 Stichting Mathematisch Centrum. All rights reserved. |
| 260 | + |
| 261 | +See the file "LICENSE" for information on the history of this software, terms & |
| 262 | +conditions for usage, and a DISCLAIMER OF ALL WARRANTIES. |
| 263 | + |
| 264 | +This Python distribution contains *no* GNU General Public License (GPL) code, |
| 265 | +so it may be used in proprietary projects. There are interfaces to some GNU |
| 266 | +code but these are entirely optional. |
| 267 | + |
| 268 | +All trademarks referenced herein are property of their respective holders. |
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