Replacing multiple regex patterns together

Question

I have a long string where I want to replace dozens of regex expressions so I created a dictionary like this:

replacements = { r'\spunt(?!\s*komma)' : r".",
                 r'punt komma' : r",",
                 r'(?<!punt )komma' : r",",
                 "paragraaf" : "\n\n" }

The above dictionary is a little selection.

How could i apply this to a document of strings? An example string:

text = ""a punt komma is in this case not a komma and thats it punt"

I tried something like this:

import re 

def multiple_replace(dict, text):
  # Create a regular expression  from the dictionary keys
  regex = re.compile("(%s)" % "|".join(map(re.escape, dict.keys())))

  # For each match, look-up corresponding value in dictionary
  return regex.sub(lambda mo: dict[mo.string[mo.start():mo.end()]], text) 

if __name__ == "__main__": 

  text = "Larry Wall is the creator of Perl"

  dict = {
    "Larry Wall" : "Guido van Rossum",
    "creator" : "Benevolent Dictator for Life",
    "Perl" : "Python",
  } 

  print(multiple_replace(dict, text))

But this works only on string replacement and not a regex pattern like my dictionary.

Answer 1

Iterate your dictionary, then make a substitution using each key, value pair:

replacements = { r'\spunt(?!\s*komma)' : r".",
                 r'punt komma' : r",",
                 r'(?<!punt )komma' : r",",
                 "paragraaf" : "\n\n" }

text = "a punt komma is in this case not a komma and thats it punt"
print(text)

for key, value in replacements.items():
    text = re.sub(key, value, text)

print(text)

This outputs:

a punt komma is in this case not a komma and thats it punt
a , is in this case not a , and thats it.

Note that you probably should be word boundaries \b around each key regex term, to avoid matching an unintentional substring.