validators.py 文件源码

def __init__(self, expression, error_message='Invalid expression',
                 strict=False, search=False, extract=False,
                 is_unicode=False):

        if strict or not search:
            if not expression.startswith('^'):
                expression = '^(%s)' % expression
        if strict:
            if not expression.endswith('$'):
                expression = '(%s)$' % expression
        if is_unicode:
            if not isinstance(expression, unicode):
                expression = expression.decode('utf8')
            self.regex = re.compile(expression, re.UNICODE)
        else:
            self.regex = re.compile(expression)
        self.error_message = error_message
        self.extract = extract
        self.is_unicode = is_unicode