Passing info to function used in re.sub

[MRAB]

On 2023-09-03 17:10, Jan Erik Moström via Python-list wrote:
> I'm looking for some advice for how to write this in a clean way
> 
> I want to replace some text using a regex-pattern, but before creating replacement text I need to some file checking/copying etc. My code right now look something like this:
> 
> def fix_stuff(m):
> 	# Do various things that involves for info
> 	# that what's available in m
> 	replacement_text = m.group(1) + global_var1 + global_var2
> 	return replacement_text
> 
> and the call comes here
> 
> global_var1 = "bla bla"
> global_var2 = "pff"
> 
> new_text = re.sub(im_pattern,fix_stuff,md_text)
> 
> 
> The "problem" is that I've currently written some code that works but it uses global variables ... and I don't like global variables. I assume there is a better way to write this, but how?
> 
You could use pass an anonymous function (a lambda) to re.sub:

     def fix_stuff(m, var1, var2):
         # Do various things that involves for info
         # that what's available in m
         replacement_text = m.group(1) + var1 + var2
         return replacement_text

     global_var1 = "bla bla"
     global_var2 = "pff"

     new_text = re.sub(im_pattern, lambda m, var1=global_var1, 
var2=global_var2: fix_stuff(m, var1, var2), md_text)

Or, if you prefer a named function, define one just before the re.sub:

     def fix_stuff(m, var1, var2):
         # Do various things that involves for info
         # that what's available in m
         replacement_text = m.group(1) + var1 + var2
         return replacement_text

     global_var1 = "bla bla"
     global_var2 = "pff"

     def fix_it(m, var1=global_var1, var2=global_var2):
         return fix_stuff(m, var1, var2)

     new_text = re.sub(im_pattern, fix_it, md_text)