peter at engcorp.com
Thu Jun 2 15:58:34 CEST 2005
qscomputing at gmail.com wrote:
> I've developed in several other languages and have recently found
> Python and I'm trying to use it in the shape of the PythonCard
> application development tool.
> My two questions:
> 1. What is the easiest way to create a for loop in the style I'm used
> to from Delphi ie:
> for I:=0 to 2 do begin
for i in xrange(0, 3):
Please read the tutorial. I'm fairly sure this and many more things
you'll want to know are covered adequately.
> 2. Philospohy(sp?) aside, I could potentially want to create a
> binary-only distribution of my finished apps. I noticed the
> documentation on .pyc files: how do I create these and, aside from
> being basically read-only, are they used just like ordinary .py source
> files? And can they be easily reverse-engineered?
They are compiled versions of the .py files, so definitely not the same.
They are created automatically and transparently when you import .py
modules, so normally you don't pay any attention to them. They can
easily be reverse-engineered, if by that you mean turned back into
source code. See "decompyle" for example. Using the "compileall"
module you can manually compile .py to .pyc but, again, that's generally
not needed. Use of tools like py2exe is generally advised for packaging
and distibution if you don't want to distribute source, though few of
the existing tools do much more than package up .pyc files inside
archives, bundle the runtime library, and add wrapper code to make the
Philosophy not entirely aside, you should note that object code in any
language can "easily" be reverse-engineered in the same way, with the
only difference being the degree of ease involved. If the code is worth
enough to someone that they are willing to risk violating your license
terms, they *will* be able to recover enough source code (whether it was
Python, C, or assembly) to do what they need. The only certain
protection is to keep the valuable code on a server and use some kind of
web service (or whatever) to control access to its execution. (There
have been *many* past discussions of all this in the forum -- it's a
very tired topic by now -- so please feel free to peruse the archives
via Google Groups before asking lots of the same questions over again.
You'll be doing yourself a favour.)
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