pbx mask formatter class (prototype)

__init__.py

class MaskFormatter(object):

    def __init__(self, **variables):
        self.variables = variables
        self.formatter = string.Formatter()

    def format(self, match_pattern, strip_length, prepend_prefix):
        mask_parts = []
        for literal_text, field_name, _, _ in self.formatter.parse(prepend_prefix):
            if literal_text:
                mask_parts.append(literal_text)

            if field_name and field_name in self.variables:
                mask_parts.append(unicode(self.variables[field_name]))

        for literal_text, field_name, _, _ in self.formatter.parse(match_pattern):
            if literal_text:
                if strip_length:
                    literal_text_len = len(literal_text)
                    if literal_text_len >= strip_length:
                        literal_text = literal_text[strip_length:]
                        strip_length = 0
                    else:
                        strip_length -= literal_text_len
                    mask_parts.append(literal_text)

            if field_name and field_name in self.variables:
                if strip_length:
                    strip_length -= 1
                else:
                    mask_parts.append(unicode(self.variables[field_name]))

        return ''.join(mask_parts)