1 try:

     2     import idlelib.PyShell

     3 except ImportError:

     4     # IDLE is not installed, but maybe PyShell is on sys.path:

     5     try:

     6         import PyShell

     7     except ImportError:

     8         raise

     9     else:

    10         import os

    11         idledir = os.path.dirname(os.path.abspath(PyShell.__file__))

    12         if idledir != os.getcwd():

    13             # We're not in the IDLE directory, help the subprocess find run.py

    14             pypath = os.environ.get('PYTHONPATH', '')

    15             if pypath:

    16                 os.environ['PYTHONPATH'] = pypath + ':' + idledir

    17             else:

    18                 os.environ['PYTHONPATH'] = idledir

    19         PyShell.main()

    20 else:

    21     idlelib.PyShell.main()