Need to write python source with python

Tue Feb 28 14:25:33 EST 2012

crstop at gmail.com wrote:
> On Tuesday, February 28, 2012 9:56:43 AM UTC-8, Peter Otten wrote:
>> crstop at gmail.com wrote:
>>>> > I'm new to Python but have experience with a few other programming
>> > languages(Java, Perl, JavaScript).
>> > 
>> > I'm using Python 2.7.2 and I'm trying to create and write to a file
>> > (.py) a python class and functions from python. I will also need to
>> > later read and edit the file. I realize I could just write strings
>> > using the available string and file writing methods but suspect there
>> > is a better way than that.
>> > 
>> > I have read about pickle, ast, and Django; searched this group and the
>> > web but haven't found a solution that seems to fit. Any suggestion?
>>>> Due to Python's dynamic nature it is rarely necessary to generate Python
>> code. What are you actually trying to achieve?
>> I'm trying to generate the script file that will launch a PythonCard
> resource file.
>> very basic example from the documentation.
>> #!/usr/bin/python
> """
> __version__ = "$Revision: 1.10 $"
> __date__ = "$Date: 2004年04月24日 22:13:31 $"
> """
>> from PythonCard import model
>> class Minimal(model.Background):
> pass
>> if __name__ == '__main__':
> app = model.Application(Minimal)
> app.MainLoop()

If it doesn't get too complex you could start with Python's built-in string 
formatting:
import sys
template = '''\
#!/usr/bin/python
from PythonCard import model
class {Class}(model.Background):
 pass
if __name__ == '__main__':
 app = model.Application({Class})
 app.MainLoop()
'''
resourcename, filename = sys.argv[1:]
with open(resourcename, "U") as f:
 data = eval(f.read())
with open(filename, "w") as f:
 f.write(template.format(Class=data["application"]["name"]))
If you need logic inside the template, here's on overview: 
http://wiki.python.org/moin/Templating
So there are rather too many options than too few.