Python command line?

[Jeff Epler]

On Tue, Jun 04, 2002 at 10:59:18AM -0500, SA wrote:
> Hi Everyone-
> 
> I would like to run python code line by line using:
> 
> python -c some line of code
> 
> Will this work?

Probably not.  For instance,
    python -c 'def f(): return 3'
    python -c 'print f()'
won't do the same thing as
    >>> def f(x): return 3
    ...
    >>> print f(x)
    3
You probably need to use 'eval' or 'exec':
    >>> gns = {'__builtins__': __builtins__} 
    >>> lns = {}
    >>> exec "def f(): return 3" in gns, lns
    >>> exec "print f()" in gns, lns
    3
    >>> print lns['f']()  # Or access items created in the local namespace
    3

Jeff
PS you escape all sorts of quoting and length-limit problems by avoiding
the likes of os.system("python -c '%s'", cmdstr) too -- for instance,
this won't work at all on NT (since ''-quoting doesn't exist in the
shell afaik) and the cmdstr of "'; echo '0wn3d" will not do what you
want on Unix.