type_hint_error.py

from typing import List, Dict
import sys

def get_profile_a(user_id: int, likes: Dict[str, int]) -> Dict[str, int]:
    return {'user_id': user_id, 'likes': len(likes)}

def get_profile_b(user_id, likes):
    return {'user_id': user_id, 'likes': len(likes.keys())}

if len(sys.argv) > 1:
    get_profile_a()
else:
    get_profile_b()
    
# Without type hints    
    
'''
➜  cpython git:(error-message-annotations) ✗ ./python foo_signature.py
Traceback (most recent call last):
  File "foo_signature.py", line 13, in <module>
    get_profile_b()
TypeError: get_profile_b() missing 2 required positional arguments: 'user_id' and 'likes'
'''

# With type hints

'''
➜  cpython git:(error-message-annotations) ✗ ./python foo_signature.py types
Traceback (most recent call last):
  File "foo_signature.py", line 11, in <module>
    get_profile_a()
TypeError: get_profile_a() missing 2 required positional arguments: 'user_id' and 'likes'
annotation: (user_id: <class 'int'>, likes: typing.Dict[str, int], return: typing.Dict[str, int])
'''