How to create new folder?

You can create a folder with os.makedirs()
and use os.path.exists() to see if it already exists:

newpath = r'C:\Program Files\arbitrary' 
if not os.path.exists(newpath):
    os.makedirs(newpath)

If you're trying to make an installer: Windows Installer does a lot of work for you.

Have you tried os.mkdir?

You might also try this little code snippet:

mypath = ...
if not os.path.isdir(mypath):
   os.makedirs(mypath)

makedirs creates multiple levels of directories, if needed.

You probably want os.makedirs as it will create intermediate directories as well, if needed.

import os

#dir is not keyword
def makemydir(whatever):
  try:
    os.makedirs(whatever)
  except OSError:
    pass
  # let exception propagate if we just can't
  # cd into the specified directory
  os.chdir(whatever)