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 use a function object.

 class A(object):
  def __init__(self, mappings):
    self.mappings = mappings
  def __call__(self, match):
    return str(eval(match.group(0)[2:-1], self.mappings))

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