The Python programming language is used in each version of ArcGIS since 9.0, and is incorporated into the automatic installation of ArcMap and ArcGIS for Server. ArcGIS installs the versions of Python listed below during a complete installation process.
The following lists the versions of Python used in each version of ArcGIS since 10.0.
It is not recommended to install an independent version of Python for use in ArcGIS. Using a different version of Python can lead to compatibility issues and root folder problems.
The version of Python used in any version of ArcGIS Pro can be determined by opening the Python window in the application (View > Python) and typing the following commands:
The commands return a line of code which displays the default Python version used with the application. In the image below, the version used is 3.5.2 (major=3, minor=5, micro=2).
ArcGIS (for) Desktop
10.6 - Python 2.7.14 and Numerical Python 1.9.3
10.5.1 - Python 2.7.13 and Numerical Python 1.9.3
10.5 - Python 2.7.12 and Numerical Python 1.9.3
10.4.x - Python 2.7.10 and Numerical Python 1.9.2
10.3.x - Python 2.7.x and Numerical Python 1.7.x required; 2.7.8 and 1.7.1 are installed if the version requirement is not met
10.2.x - Python 2.7.5 and Numerical Python 1.7.1
10.2 - Python 2.7.3 and Numerical Python 1.6.1
10.1 - Python 2.7.2 and Numerical Python 1.6.1
10 - Python 2.6.5 and Numerical Python 1.3.0
ArcGIS Enterprise / ArcGIS Server
10.6 - Python 2.7.14, Numerical Python 1.9.3, and Matplotlib 1.5.2
10.5.1 - Python 2.7.13, Numerical Python 1.9.3, and Matplotlib 1.5.2
10.5 - Python 2.7.12, Numerical Python 1.9.3, and Matplotlib 1.5.2
10.4.x - Python 2.7.10, Numerical Python 1.9.2, and Matplotlib 1.4.3
10.3.x - Python 2.7.8, Numerical Python 1.7.1, and Matplotlib 1.3.0