On Mac OS X using the python.org installer as you apparently have, you need to invoke Python 3 with python3, not python. That is currently reserved for Python 2 versions. That is currently reserved for Python 2 versions. Later during the runtime, either use python 3 command or python in python 3 virtual env. Use either pip3 or pip3.x (pip3.6 for example) to install packages based on the installed Python 3 version.

Source code:Lib/sysconfig.py

The sysconfig module provides access to Python’s configurationinformation like the list of installation paths and the configuration variablesrelevant for the current platform.

Configuration variables¶

A Python distribution contains a Makefile and a pyconfig.hheader file that are necessary to build both the Python binary itself andthird-party C extensions compiled using distutils.

sysconfig puts all variables found in these files in a dictionary thatcan be accessed using get_config_vars() or get_config_var().

Notice that on Windows, it’s a much smaller set.

With no arguments, return a dictionary of all configuration variablesrelevant for the current platform.

With arguments, return a list of values that result from looking up eachargument in the configuration variable dictionary.

For each argument, if the value is not found, return None.

Return the value of a single variable name. Equivalent toget_config_vars().get(name).

If name is not found, return None.

Example of usage:

Installation paths¶

Python uses an installation scheme that differs depending on the platform and onthe installation options. These schemes are stored in sysconfig underunique identifiers based on the value returned by os.name.

Every new component that is installed using distutils or aDistutils-based system will follow the same scheme to copy its file in the rightplaces.

Python currently supports seven schemes:

• posix_prefix: scheme for POSIX platforms like Linux or Mac OS X. This isthe default scheme used when Python or a component is installed.

• posix_home: scheme for POSIX platforms used when a home option is usedupon installation. This scheme is used when a component is installed throughDistutils with a specific home prefix.

• posix_user: scheme for POSIX platforms used when a component is installedthrough Distutils and the user option is used. This scheme defines pathslocated under the user home directory.

• nt: scheme for NT platforms like Windows.

• nt_user: scheme for NT platforms, when the user option is used.

Each scheme is itself composed of a series of paths and each path has a uniqueidentifier. Python currently uses eight paths:

• stdlib: directory containing the standard Python library files that are notplatform-specific.

• platstdlib: directory containing the standard Python library files that areplatform-specific.

• platlib: directory for site-specific, platform-specific files.

• purelib: directory for site-specific, non-platform-specific files.

• include: directory for non-platform-specific header files.

• platinclude: directory for platform-specific header files.

• scripts: directory for script files.

• data: directory for data files.

sysconfig provides some functions to determine these paths.

Return a tuple containing all schemes currently supported insysconfig.

Return a tuple containing all path names currently supported insysconfig.

Mac Os Update Python 2

Return an installation path corresponding to the path name, from theinstall scheme named scheme.

name has to be a value from the list returned by get_path_names().

sysconfig stores installation paths corresponding to each path name,for each platform, with variables to be expanded. For instance the stdlibpath for the nt scheme is: {base}/Lib.

get_path() will use the variables returned by get_config_vars()to expand the path. All variables have default values for each platform soone may call this function and get the default value.

If scheme is provided, it must be a value from the list returned byget_scheme_names(). Otherwise, the default scheme for the currentplatform is used.

If vars is provided, it must be a dictionary of variables that will updatethe dictionary return by get_config_vars().

If expand is set to False, the path will not be expanded using thevariables.

If name is not found, return None.

Return a dictionary containing all installation paths corresponding to aninstallation scheme. See get_path() for more information.

If scheme is not provided, will use the default scheme for the currentplatform.

If vars is provided, it must be a dictionary of variables that willupdate the dictionary used to expand the paths.

If expand is set to false, the paths will not be expanded.

If scheme is not an existing scheme, get_paths() will raise aKeyError.

Other functions¶

Return the MAJOR.MINOR Python version number as a string. Similar to'%d.%d'%sys.version_info[:2].

Return a string that identifies the current platform.

This is used mainly to distinguish platform-specific build directories andplatform-specific built distributions. Typically includes the OS name andversion and the architecture (as supplied by ‘os.uname()’), although theexact information included depends on the OS; e.g., on Linux, the kernelversion isn’t particularly important.

Examples of returned values:

• linux-i586

• linux-alpha (?)

• solaris-2.6-sun4u

Windows will return one of:

• win-amd64 (64bit Windows on AMD64, aka x86_64, Intel64, and EM64T)

• win32 (all others - specifically, sys.platform is returned)

Mac OS X can return:

• macosx-10.6-ppc

• macosx-10.4-ppc64

• macosx-10.3-i386

• macosx-10.4-fat

For other non-POSIX platforms, currently just returns sys.platform.

Return True if the running Python interpreter was built from source andis being run from its built location, and not from a location resulting frome.g. running makeinstall or installing via a binary installer.

Parse a config.h-style file.

fp is a file-like object pointing to the config.h-like file.

A dictionary containing name/value pairs is returned. If an optionaldictionary is passed in as the second argument, it is used instead of a newdictionary, and updated with the values read in the file.

Return the path of pyconfig.h.

Return the path of Makefile.

Using sysconfig as a script¶

You can use sysconfig as a script with Python’s -m option:

This call will print in the standard output the information returned byget_platform(), get_python_version(), get_path() andget_config_vars().

Important

If you are using a Python from any current python.orgPython installer for macOS (3.9.0+, 3.8.0+, or 3.7.2+),no further action is needed to use IDLE or tkinter.A built-in version of Tcl/Tk 8.6 will be used.

If you are using macOS 10.6 or later, the Apple-suppliedTcl/Tk 8.5 has serious bugs that can cause application crashes.If you wish to use IDLE or Tkinter, do not use the Apple-suppliedPythons. Instead, install and use a newer version of Pythonfrom python.org or a third-party distributor that supplies orlinks with a newer version of Tcl/Tk.

Python's integrated development environment,IDLE, and thetkinter GUI toolkitit uses, depend on the Tk GUI toolkit which isnot part of Python itself. For best results, it is important that theproper release of Tcl/Tk is installed on your machine.For recent Python installers for macOS downloadable from this website,here is a summary of current recommendations followed by more detailedinformation.

Python Update Mac Os 10.13

There are currently three major variants of Tk in common use on macOS:

Aqua Cocoa Tk

A newer native implementation availableas a universal 64-bit and 32-bit binary. This variant is the standard nativemacOS variant in Tk 8.6 and as of Tk 8.5.13. Aqua Cocoa support wasbackported to Tk 8.5 (prior to 8.5.13) and released by Apple starting with macOS 10.6and by ActiveState starting with their 8.5.9.1 release.

Aqua Carbon Tk

Because it is implemented with older macOS Carbon interfaces, it isonly available as a 32-bit binary (usually for Intel and PowerPCprocessors). Aqua Carbon Tk 8.4 is included with macOS releases 10.4through 10.14 and is also available from ActiveState. Aqua Carbon variantsof Tk 8.5 had been available as an ActiveState Community Download priorto ActiveTcl 8.5.9. As of 8.5.13, the Tk project no longer supportsCarbon builds of Tk 8.5. 32-bit-only Python installers downloadablefrom this website for older Python releases were linked with Aqua CarbonTk 8.4.

X11 Tk

The traditional platform-independent UNIX Tk implementation whichrequires an X11 server, such as the Apple X11.app available as anoptional component in older macOS releases or from third-partydistributors. 64-bit and32-bit binaries can be built. While the Python installers downloadablefrom this website do not support X11 Tk, other distributors ofPython for macOS may do so.

built-in 8.6.8

As of Python 3.7.0, 3.6.8, and 2.7.16, all current Python installers for macOSdownloadable from python.org supplytheir own private copies of Tcl/Tk 8.6.8. They do not look for or use anythird-party or system copies of Tcl/Tk. This is an Aqua Cocoa Tk.

ActiveTcl 8.5.18.0

ActiveState provides binary distributions of Tcl/Tk which are upward compatiblewith and generally more up-to-date than those provided by Apple in macOSreleases. This version of Tcl/Tk includes fixes for some critical problemsthat you may encounter using tkinter or IDLE (see Apple 8.5.9 below).You can download an installer for this release fromthe ActiveState web site.Note that ActiveState Community Edition binaries are not open source andare covered by an ActiveState license. You should read the licensebefore downloading to verify that your usage complies with its terms of use.As of Python 3.7.0, 3.6.8, and 2.7.16, no current Python installers for macOSdownloadable from python.org make use of this or any other external versionof Tcl/Tk.

This is an Aqua Cocoa Tk.

Apple 8.5.9

This release is included in macOS 10.7 through at least macOS 10.14.As of this writing,there are at least two known issues with Tk 8.5.9 thatare present in Apple 8.5.9 Tk but fixed in more recent upstream 8.5 releases.The more serious problem is an immediate crash in Tkwhen entering a composition character, like Option-u on a US keyboard.(This problem is documented asTk bug 2907388.)There is also the more general problem of input manager support for compositecharacters(Tk bug 3205153)which has also been fixed in more recent Tcl/Tk 8.5 releases.You can avoid these problems by using a current python.org installeror by using a third-partydistribution of Python that does not use Apple 8.5.9 Tk.This is an Aqua Cocoa Tk.

Apple 8.5.7

This release is included in macOS 10.6. IDLE is known to hang or crashwhen used with the Apple 8.5.7 included in all versions of macOS 10.6.x.Because of this,we strongly recommend that you do not attempt to use Tkinter or IDLE withthe Apple-supplied Python 2.6.1 in 10.6. Instead, install a newer version ofPython that supports a newer version of Tk.This is an Aqua Cocoa Tk.

Note

While Tcl and Tk areseparate frameworks and libraries, they are closely related and arenormally installed or updated simultaneously. You should notattempt to mix-and-match Tcl and Tk versions. References toa specific version of Tk assume the corresponding version ofTcl is installed as well.

The Python for macOS installers downloaded from this website dynamicallylink at runtime to Tcl/Tk macOS frameworks. The Tcl/Tk major version isdetermined when the installer is created and cannot be overridden.All current python.org installers for Python 3.7.x, 3.6.x,and 2.7.x link to their own built-in Tcl/Tk 8.6 frameworks and do not useexternal Tcl/Tk frameworks so the rest of this section only applies tonon-current releases and, as such, no longer supported.

The Python 64-bit/32-bit macOS installers for Python 3.6.x andand 2.7.x dynamically link to Tcl/Tk 8.5 frameworks.The dynamically linking occurs when tkinter (Python 3)or Tkinter (Python 2) is first imported (specifically, the internal_tkinter C extension module). By default, the macOS dynamic linkerlooks first in /Library/Frameworks for Tcl and Tk frameworks withthe proper major version. This is the standard location for third-partyor built from source frameworks, including the ActiveTcl releases.If frameworks of the proper major version are not found there,the dynamic linker looks for the same version in/System/Library/Frameworks, the location for Apple-suppliedframeworks shipped with macOS. (Note, you should normally not modifyor delete files in /System/Library.)

As is common on macOS, the installed Pythons and the Tcl and Tkframeworks are built to run on multiple CPU architectures (universalbinaries) and across multiple macOS levels (minimum deploymenttarget). For Python to be able to dynamically link with a particularTcl and Tk version, the available architectures in the Tcl/Tk frameworksmust include the architecture that Python is running in and theirminimum deployment target should be no greater than that of Python.

• 2020-10-05 - updated for 3.9.0 and 3.8.6, remove 2.7
• 2020-08-17 - updated for 3.7.9
• 2020-07-20 - updated for 3.8.5
• 2020-06-27 - updated for 3.7.8
• 2020-05-14 - updated for 3.8.3
• 2020-03-10 - updated for 3.8.2 and 3.7.7
• 2019-12-19 - updated for 3.8.1, 3.7.6, and 2.7.17
• 2019-10-15 - updated for 3.8.0, 3.7.5, and macOS 10.15
• 2019-07-08 - updated for 3.7.4; 3.6.x is now security-fix-only
• 2019-03-25 - updated for 3.7.3
• 2019-03-03 - updated for 2.7.16
• 2018-12-24 - updated for 3.7.2 and 3.6.8
• 2018-10-20 - updated for 3.7.1, 3.6.7, and macOS 10.14
• 2018-06-27 - updated for 3.7.0 and 3.6.6
• 2018-05-30 - updated for 3.7.0b5
• 2018-05-02 - updated for 3.7.0b4 and 2.7.15; removed 32-bit-only refs
• 2018-03-29 - updated for 3.7.0b3 and 3.6.5
• 2018-02-28 - updated for 3.7.0b2
• 2018-01-31 - updated for 3.7.0b1 and 3.6.4
• 2017-10-03 - updated for 3.6.3 and macOS 10.13
• 2017-09-16 - updated for 2.7.14; removed 3.5.x
• 2017-07-17 - updated for 3.6.2
• 2017-03-21 - updated for 3.6.1 and (belatedly) 3.5.3
• 2016-12-23 - updated for 3.6.0
• 2016-12-17 - updated for 2.7.13
• 2016-09-23 - updated for macOS 10.12
• 2016-07-31 - updated for 3.5.2 and 2.7.12; removed 3.4.x
• 2015-12-20 - updated for 3.4.4
• 2015-12-06 - updated for 3.5.1, 2.7.11, and macOS 10.11
• 2015-09-13 - updated for 3.5.0
• 2015-05-23 - updated for 2.7.10 and ActiveTcl 8.5.18.0
• 2015-02-23 - updated for 3.4.3
• 2014-12-10 - updated for 2.7.9 and ActiveTcl 8.5.17.0
• 2014-10-16 - updated for macOS 10.10
• 2014-10-06 - updated for 3.4.2 and ActiveTcl 8.5.16.0
• 2014-09-22 - updated for 3.4.2rc1
• 2014-07-01 - updated for 2.7.8
• 2014-06-01 - updated for 2.7.7; removed 2.7.6 and 3.3.5
• 2014-05-18 - updated for 3.4.1 and 2.7.7rc1
• 2014-03-16 - updated for 3.4.0 and 3.3.5
• 2014-02-10 - updated for 3.3.4 and 3.4.0rc1
• 2014-01-05 - updated for 3.4.0b2
• 2013-11-24 - clarify that the ActiveState website still refers to 8.5.15.0
• 2013-11-24 - removed built-in for 3.4.0b1, removed 3.3.2 and 2.7.5
• 2013-11-10 - ActiveTcl 8.5.15.1; removed built-in for 3.3.3rc2 and 2.7.6.
• 2013-10-27 - updated for 3.3.3rc1 and 2.7.6rc1 and their built-in 8.5.15.
• 2013-10-24 - updated for macOS 10.9 and ActiveTcl 8.5.15, removed 3.2.5.
• 2013-10-20 - updated for 3.4.0a4 and its built-in 8.5.15.
• 2013-09-29 - updated for 3.4.0a3
• 2013-09-09 - updated for 3.4.0a2 and its built-in 8.5.14.
• 2013-08-03 - updated for 3.4.0a1 and ActiveTcl 8.4.20
• 2013-05-18 - updated for ActiveTcl 8.5.14
• 2013-05-15 - updated for 3.3.2, 2.7.5, and 3.2.5
• 2013-04-06 - updated for 3.3.1, 2.7.4, and 3.2.4
• 2012-12-26 - updated for ActiveTcl 8.5.13 and Issue 15853 patch installer
• 2012-09-29 - updated for 3.3.0 final and reverted to ActiveTcl 8.5.11.1
• 2012-08-02 - updated for ActiveTcl 8.5.12
• 2012-07-28 - updated for macOS 10.8
• 2012-04-11 - updated for 3.2.3 final and 2.7.3 final
• 2012-03-18 - updated for 3.2.3rc2 and 2.7.3rc2
• 2012-03-04 - updated for ActiveTcl 8.5.11.1, 3.2.3rc1, 2.7.3rc1, removed 3.1.4
• 2011-11-12 - updated for ActiveTcl 8.5.11
• 2011-09-04 - updated for 3.2.2 final
• 2011-07-21 - updated for macOS 10.7 and ActiveTcl 8.5.10.1
• 2011-07-09 - updated for 3.2.1 final and ActiveTcl 8.5.10
• 2011-06-12 - updated for 2.7.2 final and 3.1.4 final
• 2011-05-30 - updated for 3.2.1rc, 2.7.2rc, and 3.1.4rc
• 2011-03-08 - add warnings and include details on how Python links with Tcl/Tk releases
• 2011-02-20 - updated for 3.2 final
• 2011-01-31 draft 1 - preliminary info for 3.2rc2
• 2011-01-14 draft 0