理解module search path in Python

• module search path

  When the interpreter executes import statement(like import sys) from any module, it searches for sys.py in a list of directories assembled from the following sources:

  • The directory from which the input script was run, or the current directory if the interpreter is being run interactively

  • The list of directories contained in the PYTHONPATH environment variable, if it is set.(The format for PYTHONPATH is OS-dependent but should mimic the PATH environment)

  • An installation-dependent list of directories configured configured at the time Python is installed

• how to get it

  The resulting search path is accessible in the Python variable sys.path, which is obetained from a module named sys: