text manipulation

[Juho Schultz]

Johhny wrote:
> Hello,
> 
> I am trying to write a script in python (to replace a perl script with
> limited functionality). Now I have some issues. Currently I am using
> the perl to load the file then regex parse certain lines to remove
> characters (uncomment lines and change variables). I would like to take
> that into the python script. I have had a look at the module "string"
> and I dont think its what Im looking for.
> 
> Here is an example of some text I would like to manipulate
> 
> #comment here
> #user_defined_variable = no
> #
> 
> I would like to make that
> 
> #comment here
> user_defined_variable = yes
> #
> 
> With perl/sed Its very easy, However Im having issues to do it in
> python. Any advice would be great.
> 
> Regards,
> 
> Johhny.
> 

Have you also looked at the built-in string methods?


The following script is probably something you
could start with - it just uncomments lines
and replaces values of some variables.

# dictionary of the variable names
# contains the replacement values
newvalues = {'userdefinedvar1':'yes',
'userdefinedvar2':'123.654.345.234'}

# read file to input
output = []
for line in input:
     # check if it is a comment with "="
     if line.startswith('#') and ('=' in line):
         name, oldvalue = (line.lstrip('#')).split('=')
         # line.lstrip removes leading comments,
         # split('=') finds the assignment
         if newvalues.has_key(name):
             # replace line
             output.append("%s = %s" % (name, newvalue[name]))
         else:
             # or just uncomment
             output.append("%s = %s" % (name, oldvalue))
     else:
         output.append(line)

# write output to file