How to pass a variable to a re.sub callback?

Question

I am using a re.sub callback to replace substrings with random values, but I would like the random values to be the same across different strings. Since the re.sub callback does

Answer 1

You could create a closure.

def evaluator(mappings):
  def f(match):
    return str(eval(match.group(0)[2:-1], mappings))
  return f

evaluate = evaluator({'A': 1, 'B': 2})

Since f is just a single statement, you could simply use lambda:

def evaluator(mappings):
  return lambda match: str(eval(match.group(0)[2:-1], mappings))