/Lib/idlelib/idle.py

 1try:
 2    import idlelib.PyShell
 3except 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()
20else:
21    idlelib.PyShell.main()