Build CPython on Windows

Guide to build the master branch of CPython. Other Python versions need a different Visual Studio version.

To develop on CPython, the best is to enable all debug checks and so compile Python in “debug mode”.

Install tools and dependencies

Build CPython in the IDE

  • Open Visual Studio
  • Open PCbuild/pcbuild.sln solution
  • Select Debug and x64 (64-bit)
  • Right click on the solution: Build, or just “F10”
  • Close Visual Studio

Build CPython in the command line

  • Open a terminal (like cmd.exe)
  • Type: PCbuild\build.bat -e -d -p x64
    • -e: download external dependencies (OpenSSL, Tkinter, …)
    • -d: build in debug mode (Py_DEBUG, enable assertions, …)
    • -x p64: build in 64-bit mode

Run Python

  • Open a terminal: run cmd.exe
  • Go to the Python directory
  • Run PCbuild\amd64\python_d.exe
  • Try to import the ssl module: import ssl. If the ssl module is available, you are good. Otherwise, you missed maybe the “get_externals.bat” step?

Your python_d.exe works? Great! Let’s move to the next section.