Transform a piece of text by appling an ordered list of string transformations to input text

text_transforms.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import re
from itertools import chain
from functools import reduce, partial


def apply_substitutions(text, substitutions):
    """Apply an ordered list of string transformations to input text

    Given some text and a list of tuples in the form
        [(<regex_pattern>, <substitution>), ....]
    returns the text with all the specified substitutions performed.
    """
    transforms = (partial(re.sub, p, s) for p, s in substitutions)
    return reduce(lambda t, sub: sub(t), iter(transforms), text)

if __name__ == '__main__':
    assert(
        apply_substitutions(
            'this is a xxx yyy',
            (
                ('xxx', 'cool'),
                ('yyy', 'tool'),
                (r'.*', lambda match: match.group().title()),
            )
        ) == 'This Is A Cool Tool'
    )