I noticed importing an executable Python file saves a *.py[co] file, as expected, but that file also is marked executable.  Randomly, I wondered if I could execute this file directly, and it worked!  

Duplicate:

    $ touch empty.py; chmod u+x empty.py
    $ python -c 'import empty'
    $ ls -og empty.py
    -rwxr----- 1  0 2009-11-21 15:25 empty.py*
    -rwxr----- 1 95 2009-11-21 15:25 empty.pyc*
    $ ./empty.pyc

(There isn't any output, as expected.)

How?  Is my system, Ubuntu 9.04, doing something special, or am I forgetting something on how Linux works in general?

    $ python --version
    Python 2.6.2
    $ hd empty.pyc
    00000000  d1 f2 0d 0a ae 41 08 4b  63 00 00 00 00 00 00 00  |.....A.Kc.......|
    00000010  00 01 00 00 00 40 00 00  00 73 04 00 00 00 64 00  |.....@...s....d.|
    00000020  00 53 28 01 00 00 00 4e  28 00 00 00 00 28 00 00  |.S(....N(....(..|
    00000030  00 00 28 00 00 00 00 28  00 00 00 00 73 08 00 00  |..(....(....s...|
    00000040  00 65 6d 70 74 79 2e 70  79 74 08 00 00 00 3c 6d  |.empty.pyt....<m|
    00000050  6f 64 75 6c 65 3e 01 00  00 00 73 00 00 00 00     |odule>....s....|
    0000005f