-(BOOL)passWordprdicateString:(NSString *)str{
    NSString * email = str;
    NSString * regex = @"^(?![0-9]+$)(?![a-zA-Z]+$)(?![\\W]+$)[a-zA-Z0-9\\W]{8,20}";
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];
    BOOL isValid = [predicate evaluateWithObject:email];
    NSLog(@"--------%ld",isValid);
    return isValid;
}