We should probably have a 
```
def verify_password(password, confirm_password):
  if len(password) < 6:
    return "Password must be at least 6 characters long."
  if password!=confirm_password:
    return "Passwords do not match."
```
Invoked as
```
error_message = verify_password(password, confirm_password)
if error_message is not None:
  return (False, error_message)
```
Or maybe just use [WTForms](http://wtforms.readthedocs.org/)