Python was created in the early 1990s by Guido van Rossum at Stichting Mathematisch Centrum (CWI, see http://www.cwi.nl) in the Netherlands as a successor of a language called ABC. Guido remains Python's principal author, although it includes many contributions from others.\
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In 1995, Guido continued his work on Python at the Corporation for National Research Initiatives (CNRI, see http://www.cnri.reston.va.us) in Reston, Virginia where he released several versions of the software.\
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@@ -20,10 +21,10 @@ In May 2000, Guido and the Python core development team moved to BeOpen.com to f
All Python releases are Open Source (see http://www.opensource.org for the Open Source Definition). Historically, most, but not all, Python releases have also been GPL-compatible; the table below summarizes the various releases.\
\
\f1\b Release Derived Year Owner GPL-\
\f2\b Release Derived Year Owner GPL-\
from compatible?\
\f2\b0 \
\f3\b0 \
0.9.0 thru 1.2 n/a 1991-1995 CWI yes\
1.3 thru 1.5.2 1.2 1995-1999 CNRI yes\
1.6 1.5.2 2000 CNRI no\
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@@ -36,25 +37,25 @@ All Python releases are Open Source (see http://www.opensource.org for the Open
2.1.3 2.1.2 2002 PSF yes\
2.2 and above 2.1.1 2001-now PSF yes\
\f0 \
\f1 \
\b Note:
\b0 GPL-compatible doesn't mean that we're distributing Python under the GPL. All Python licenses, unlike the GPL, let you distribute a modified version without making your changes open source. The GPL-compatible licenses make it possible to combine Python with other software that is released under the GPL; the others don't.\
\f0\b Note:
\f1\b0 GPL-compatible doesn't mean that we're distributing Python under the GPL. All Python licenses, unlike the GPL, let you distribute a modified version without making your changes open source. The GPL-compatible licenses make it possible to combine Python with other software that is released under the GPL; the others don't.\
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Thanks to the many outside volunteers who have worked under Guido's direction to make these releases possible.\
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\
\b \ul TERMS AND CONDITIONS FOR ACCESSING OR OTHERWISE USING PYTHON\
\f0\b \ul TERMS AND CONDITIONS FOR ACCESSING OR OTHERWISE USING PYTHON\
\b0 \ulnone \
\f1\b0 \ulnone \
\b PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2\
\f0\b PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2\
\b0 \
\f1\b0 \
1. This LICENSE AGREEMENT is between the Python Software Foundation ("PSF"), and the Individual or Organization ("Licensee") accessing and otherwise using this software ("Python") in source or binary form and its associated documentation.\
\
2. Subject to the terms and conditions of this License Agreement, PSF hereby grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce, analyze, test, perform and/or display publicly, prepare derivative works, distribute, and otherwise use Python alone or in any derivative version, provided, however, that PSF's License Agreement and PSF's notice of copyright, i.e., "Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017 Python Software Foundation; All Rights Reserved" are retained in Python alone or in any derivative version prepared by Licensee.\
2. Subject to the terms and conditions of this License Agreement, PSF hereby grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce, analyze, test, perform and/or display publicly, prepare derivative works, distribute, and otherwise use Python alone or in any derivative version, provided, however, that PSF's License Agreement and PSF's notice of copyright, i.e., "Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Python Software Foundation; All Rights Reserved" are retained in Python alone or in any derivative version prepared by Licensee.\
\
3. In the event Licensee prepares a derivative work that is based on or incorporates Python or any part thereof, and wants to make the derivative work available to others as provided herein, then Licensee hereby agrees to include in any such work a brief summary of the changes made to Python.\
\
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@@ -70,9 +71,9 @@ Thanks to the many outside volunteers who have worked under Guido's direction to
\
\
\b BEOPEN.COM LICENSE AGREEMENT FOR PYTHON 2.0\
\f0\b BEOPEN.COM LICENSE AGREEMENT FOR PYTHON 2.0\
\b0 \
\f1\b0 \
BEOPEN PYTHON OPEN SOURCE LICENSE AGREEMENT VERSION 1\
\
1. This LICENSE AGREEMENT is between BeOpen.com ("BeOpen"), having an office at 160 Saratoga Avenue, Santa Clara, CA 95051, and the Individual or Organization ("Licensee") accessing and otherwise using this software in source or binary form and its associated documentation ("the Software").\
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@@ -91,9 +92,9 @@ BEOPEN PYTHON OPEN SOURCE LICENSE AGREEMENT VERSION 1\
\
\
\b CNRI LICENSE AGREEMENT FOR PYTHON 1.6.1\
\f0\b CNRI LICENSE AGREEMENT FOR PYTHON 1.6.1\
\b0 \
\f1\b0 \
1. This LICENSE AGREEMENT is between the Corporation for National Research Initiatives, having an office at 1895 Preston White Drive, Reston, VA 20191 ("CNRI"), and the Individual or Organization ("Licensee") accessing and otherwise using Python 1.6.1 software in source or binary form and its associated documentation.\
\
2. Subject to the terms and conditions of this License Agreement, CNRI hereby grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce, analyze, test, perform and/or display publicly, prepare derivative works, distribute, and otherwise use Python 1.6.1 alone or in any derivative version, provided, however, that CNRI's License Agreement and CNRI's notice of copyright, i.e., "Copyright (c) 1995-2001 Corporation for National Research Initiatives; All Rights Reserved" are retained in Python 1.6.1 alone or in any derivative version prepared by Licensee. Alternately, in lieu of CNRI's License Agreement, Licensee may substitute the following text (omitting the quotes): "Python 1.6.1 is made available subject to the terms and conditions in CNRI's License Agreement. This Agreement together with Python 1.6.1 may be located on the Internet using the following unique, persistent identifier (known as a handle): 1895.22/1013. This Agreement may also be obtained from a proxy server on the Internet using the following URL: http://hdl.handle.net/1895.22/1013".\
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@@ -114,9 +115,9 @@ BEOPEN PYTHON OPEN SOURCE LICENSE AGREEMENT VERSION 1\
\
\
\b CWI LICENSE AGREEMENT FOR PYTHON 0.9.0 THROUGH 1.2\
\f0\b CWI LICENSE AGREEMENT FOR PYTHON 0.9.0 THROUGH 1.2\
\b0 \
\f1\b0 \
Copyright (c) 1991 - 1995, Stichting Mathematisch Centrum Amsterdam, The Netherlands. All rights reserved.\
\
Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of Stichting Mathematisch Centrum or CWI not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission.\
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@@ -125,18 +126,18 @@ STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFT
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\b \ul LICENSES AND ACKNOWLEDGEMENTS FOR INCORPORATED SOFTWARE\
\f0\b \ul LICENSES AND ACKNOWLEDGEMENTS FOR INCORPORATED SOFTWARE\
\b0 \ulnone \
\f1\b0 \ulnone \
This installer incorporates portions of the following third-party software:\
\
\f2 $THIRD_PARTY_LIBS\
\f3 $THIRD_PARTY_LIBS\
\
\f0 For licenses and acknowledgements for these and other third-party software incorporated in this Python distribution, please refer to the on-line documentation {\field{\*\fldinst{HYPERLINK "https://docs.python.org/$VERSION/license.html#licenses-and-acknowledgements-for-incorporated-software"}}{\fldrslt here}}.\
\f1 For licenses and acknowledgements for these and other third-party software incorporated in this Python distribution, please refer to the on-line documentation {\field{\*\fldinst{HYPERLINK "https://docs.python.org/$VERSION/license.html#licenses-and-acknowledgements-for-incorporated-software"}}{\fldrslt here}}.\
\f1\b \cf0 \ul \ulc0 Which installer variant should I use? [CHANGED in 2.7.15]
\f0\b0 \ulnone \
\
With Python 2.7.15, the python.org website now provides two installer variants for download: one that installs a
\f2\i 64-bit-only
\f0\i0 Python capable of running on
\f2\i macOS 10.9 (Mavericks)
\f0\i0 or later; and one that installs a
\f2\i 64-bit/32-bit Intel
\f0\i0 Python capable of running on
\f2\i macOS 10.6 (Snow Leopard)
\f0\i0 or later. (This ReadMe was installed with the
\f2\i $MACOSX_DEPLOYMENT_TARGET
\f0\i0 variant.) Previous Python 2.7.x releases provided the 10.6 or later installer and a 10.5 or later 32-bit-only variant. If you are running on macOS 10.9 or later and if you have no need for compatibility with older systems, use the 10.9 variant. Use the 10.6 variant if you are running on macOS 10.6 through 10.8, if you need to maintain compatibility with previous 2.7.x releases, or if you want to produce standalone applications that can run on systems from 10.6. The Pythons installed by these installers are built with private copies of some third-party libraries not included with or newer than those in macOS itself. The list of these libraries varies by installer variant and is included at the end of the
\f3 License.rtf
\f0 file.\
\f1\b \ul \
Certificate verification and OpenSSL_[CHANGED in 2.7.15]\
\f1\b \cf0 \ul \ulc0 Certificate verification and OpenSSL\
\f0\b0 \ulnone \
This variant of Python 2.7 now includes its own private copy of OpenSSL 1.0.2. Unlike previous releases, the deprecated Apple-supplied OpenSSL libraries are no longer used. This also means that the trust certificates in system and user keychains managed by the
This package includes its own private copy of OpenSSL 1.0.2. The trust certificates in system and user keychains managed by the
\f2\i Keychain Access
\f0\i0 application and the
\f2\i security
\f0\i0 command line utility are no longer used as defaults by the Python
\f0\i0 command line utility are not used as defaults by the Python
\f3 ssl
\f0 module. A sample command script is included in
\f3 /Applications/Python 2.7
\f0 to install a curated bundle of default root certificates from the third-party
\f3 certifi
\f0 package ({\field{\*\fldinst{HYPERLINK "https://pypi.python.org/pypi/certifi"}}{\fldrslt https://pypi.python.org/pypi/certifi}}). Click on
\f0 package ({\field{\*\fldinst{HYPERLINK "https://pypi.org/project/certifi/"}}{\fldrslt https://pypi.org/project/certifi/}}). Double-click on
\f3 Install Certificates
\f0 to run it. If you choose to use
\f3 certifi
\f0 , you should consider subscribing to the{\field{\*\fldinst{HYPERLINK "https://certifi.io/en/latest/"}}{\fldrslt project's email update service}} to be notified when the certificate bundle is updated.\
\f0 to run it.\
\
The bundled
\f3 pip
\f0 included with the Python 2.7 installer has its own default certificate store for verifying download connections.\
\f0 has its own default certificate store for verifying download connections.\
\
\f1\b \ul Using IDLE or other Tk applications [NEW/CHANGED in 2.7.15]
\f1\b \ul Which installer variant should I use?
\f0\b0 \ulnone \
\
As of 2.7.15, the 10.9+ installer variant comes with its own private version of Tcl/Tk 8.6. It does not use system-supplied or third-party supplied versions of Tcl/Tk.\
\f1\b macOS 64-bit installer for OS X 10.9 and later
\f0\b0 .\
\
The legacy
\f1\b macOS 64-bit/32-bit installer for Mac OS X 10.6 and later
\f0\b0 variant is now deprecated. macOS 10.6 Snow Leopard was released in 2009 and has not been supported by Apple for many years including lack of security updates. It is becoming increasingly difficult to ensure new Python features and bug fixes are compatible with such old systems. Note that, due to recent Apple installer packaging changes, the 10.6+ installer pkg we provide can no longer be opened by the Apple system installer application on 10.6; 10.7 and 10.8 are not affected. We believe that there is now very little usage of this installer variant and so we would like to focus our resources on supporting newer systems. We do not plan to intentionally break Python support on 10.6 through 10.8 and we will consider bug fixes for problems found when building from source on those systems through the support window of Python 2.7.
\f1\b macOS 10.15 Catalina
\f0\b0 removes support for running 32-bit architecture programs; we do not recommend trying to use the 10.6+ variant on it and it may not install on 10.15 systems without intervention. \
Binary installer support for Mac OS X 10.5 and earlier discontinued [CHANGED for Python 2.7.15]
Using IDLE or other Tk applications
\f0\b0 \ulnone \
\
As of Python 2.7.15, binary installers from python.org no longer support Mac OS X 10.5 (Leopard) systems. Binary installer support for Mac OS X 10.3.9 (Panther) and 10.4.x (Tiger) systems was previously dropped in Python 2.7.9. Mac OS X 10.5 was originally released by Apple in 2007 and last updated in 2009 and was the last OS X release for PPC machines (G4 and G5). If needed, it is still possible to build Python from source for 10.3.9, 10.4, or 10.5.\
\
\f1\b \ul Packages installed with the system Python 2.7 are no longer searched for [CHANGED for Python 2.7.13]
\f0\b0 \ulnone \
\
As of Python 2.7.0, user-installed Python 2.7 versions from python.org installers added the system-wide site-packages directory for the Apple-supplied Python 2.7 to the end of their search path. This meant that packages installed with the system Python 2.7 could also be used by the user-installed Python 2.7. While sometimes convenient, this also often caused confusion with the implicit coupling between the two Python instances. Separately, as of macOS 10.12, Apple changed the layout of the system site-packages directory,
\f3 /Library/Python/2.7/site-packages
\f0 , in a way that can now cause installation of
\f3 pip
\f0 components to fail. To avoid the confusion and the installation failures, as of 2.7.13 user-installed Pythons no longer add
\f3 /Library/Python/2.7/site-packages
\f0 to
\f3 sys.path
\f0 . If you are using a package with both a user-installed Python 2.7 and the system Python 2.7, you will now need to ensure that separate copies of the package are installed for each instance.\
\
This package includes its own private version of Tcl/Tk 8.6. It does not use any system-supplied or third-party supplied versions of Tcl/Tk.\
\
Due to new security checks on macOS 10.15 Catalina, when launching IDLE macOS may open a window with a message
\f1\b "Python" would like to access files in your Documents folder
\f0\b0 . This is normal as IDLE uses your
\f1\b Documents
\f0\b0 folder as its default when opening and saving files; you can still choose other locations in the
\f1\b Open
\f0\b0 and
\f1\b Save
\f0\b0 file dialog windows. Click on the
\f1\b OK
\f0\b0 button to proceed.\
\f1\b \ul Installing on OS X 10.8 (Mountain Lion) or later systems [CHANGED for Python 2.7.9]
\f0\b0 \ulnone \
\
As of Python 2.7.9, installer packages from python.org are now compatible with the Gatekeeper security feature introduced in OS X 10.8. Downloaded packages can now be directly installed by double-clicking with the default system security settings. Python.org installer packages for macOS are signed with the Developer ID of the builder, as identified on {\field{\*\fldinst{HYPERLINK "https://www.python.org/downloads/"}}{\fldrslt the download page}} for this release. To inspect the digital signature of the package, click on the lock icon in the upper right corner of the
\f2\i Install Python
\f0\i0 installer window. Refer to Apple\'92s support pages for {\field{\*\fldinst{HYPERLINK "http://support.apple.com/kb/ht5290"}}{\fldrslt more information on Gatekeeper}}.\
\
\f1\b \ul Simplified web-based installs [NEW for Python 2.7.9]
\f0\b0 \ulnone \
\
With the change to the newer flat format installer package, the download file now has a
\f3 .pkg
\f0 extension as it is no longer necessary to embed the installer within a disk image (
\f3 .dmg
\f0 ) container. If you download the Python installer through a web browser, the macOS installer application may open automatically to allow you to perform the install. If your browser settings do not allow automatic open, double click on the downloaded installer file.\
\f1\b \ul \
Other changes\
\
\f1\b \ul New Installation Options and Defaults [NEW for Python 2.7.9]
\f0\b0 \ulnone \
\
The Python installer now includes an option to automatically install or upgrade
\f3 pip
\f0 , a tool for installing and managing Python packages. This option is enabled by default and no Internet access is required. If you do not want the installer to do this, select the
\f2\i Customize
\f0\i0 option at the
\f2\i Installation Type
\f0\i0 step and uncheck the
\f2\i Install or upgrade pip
\f0\i0 option. For other changes in this release, see the
\f0\b0 \ulnone For other changes in this release, see the
\f2\i What's new
\f0\i0 section in the {\field{\*\fldinst{HYPERLINK "https://www.python.org/doc/"}}{\fldrslt Documentation Set}} for this release and its
\f2\i Release Notes
\f0\i0 link for this release at {\field{\*\fldinst{HYPERLINK "https://www.python.org/downloads/"}}{\fldrslt https://www.python.org/downloads/}}.\
\
\f1\b \ul Python 3 and Python 2 Co-existence\
\f0\b0 \ulnone \
Python.org Python 2.7 and 3.x versions can both be installed on your system and will not conflict. Python 2.7 command names contain a 2 or no digit:
\f3 python2
\f0 (or
\f3 python2.7
\f0 or
\f3 python
\f0 ),
\f3 idle2
\f0 (or
\f3 idle2.7
\f0 or
\f3 idle
\f0 ),
\f3 pip2
\f0 (or
\f3 pip2.7
\f0 or
\f3 pip
\f0 ), etc. Command names for Python 3 contain a 3 in them,
\f3 python3
\f0 ,
\f3 idle3
\f0 ,
\f3 pip3
\f0 , etc. Also, installing a python.org Python 2.7 does not alter or remove any Apple-supplied system Pythons, found in
\f3 /usr/bin
\f0 .\
\
\
\f0\i0 link at {\field{\*\fldinst{HYPERLINK "https://www.python.org/downloads/"}}{\fldrslt https://www.python.org/downloads/}}.\
\f0\b0 consists of the Python programming language interpreter, plus a set of programs to allow easy access to it for macOS users including an integrated development environment
\f0\b0 consists of the {\field{\*\fldinst{HYPERLINK "https://www.python.org"}}{\fldrslt Python}} programming language interpreter and its batteries-included standard library to allow easy access to macOS features. It also includes the Python integrated development environment,
\f1\b IDLE
\f0\b0 .\
\f0\b0 . You can also use the included
\f1\b pip
\f0\b0 to download and install third-party packages from the {\field{\*\fldinst{HYPERLINK "https://pypi.org"}}{\fldrslt Python Package Index}}. \
\
\f1\b NEW in 2.7.15:
\f0\b0 two installer variants (10.9+ 64-bit-only, 10.6+ 64-/32-bit), built-in Tcl/Tk 8.6 support in the 10.9+ variant (no additional third-party downloads!), updated
\f2 pip,
\f0 built-in OpenSSL 1.0.2 (click on
At the end of this install, click on
\f2 Install Certificates
\f0 for root certificates)\
\
\f1\b CHANGED in 2.7.16:
\f0\b0 the 10.6+ variant now also uses a built-in Tcl/Tk 8.6\
\f0 to install a set of current SSL root certificates.\
\
\f1\b NOTE:
\f0\b0 This is the release candidate for Python 2.7.17. Any updates needed to support the latest release of macOS,
\f1\b 10.15 Catalina,
\f0\b0 will be provided after in 2.7.17 final.\
\f1\b NOTE: \ul Python 2 reaches end-of-life in 2020 and will no longer be supported or updated thereafter\ulnone .
\f0\b0 You should
\f1\b upgrade to Python 3
\f0\b0 as soon as you can. {\field{\*\fldinst{HYPERLINK "https://www.python.org/doc/sunset-python-2/"}}{\fldrslt Read more here}}.\
