On Windows,
To run a python module without typing "python",
--> Right click any python(*.py) file
--> Set the open with property to "python.exe"
--> Check the "always use this program for this file type"
--> Append the path of python.exe to variable environment e.g. append C:\Python27 to PATH environment variable.
To Run a python module without typing ".py" extension
--> Edit PATHEXT system variable and append ".PY" extension to the list.