Esri ships ArcGIS with Python included. Python is now an integral part of the ArcGIS system, providing a command-line interface and is a basic component of ArcGIS's geographic data processing ("geoprocessing") environment.
A large amount of out-of-the-box ArcGIS functionality requires Python, so each release of ArcGIS is linked to certain versions of Python and modules. For best results (and support), Esri recommends that you install the Python distribution shipped with ArcGIS and limit additional libraries to those that support the distribution. For example, stick with numpy 1.3 if you are running ArcGIS 10.0.
New arcgisscripting (gp)
New arcpy module
Arcpy map algebra
arcpy x32 + x64
|ArcGIS Pro 1.x||3.4.1||arcpy x64 only|
arcpy.mp for Pro App