Generates string range, analog of Perl's `print "a".."azc"`

string_range.py

from itertools import product


def string_range(first, last):
    """
    Generates string range, analog of Perl's `print "a".."azc"`
    Usage: string_range('a', 'azc')
    """
    def ascii_generator(letters):
        """
        Iterates single letters in provided single or multiple letter range
        like ab-zz, where 'ab' is an argument passed to the function.
        """
        for l in letters:
            i = ord(l)
            while i <= ord('z'):
                yield chr(i)
                i = i + 1

    min_length = len(first) - 1
    for k in range(len(last)):
        if k < min_length:
            continue
        for x in product(ascii_generator(first), repeat=k + 1):
            result = ''.join(x)
            yield result
            if result == last:
                return