how to declare variable type, C style in python

Starting with Python 3.6, you can declare types of variables and functions, like this :

explicit_number: type

or for a function

def function(explicit_number: type) -> type:
    pass

This example from this post: How to Use Static Type Checking in Python 3.6 is more explicit

from typing import Dict
    
def get_first_name(full_name: str) -> str:
    return full_name.split(" ")[0]

fallback_name: Dict[str, str] = {
    "first_name": "UserFirstName",
    "last_name": "UserLastName"
}

raw_name: str = input("Please enter your name: ")
first_name: str = get_first_name(raw_name)

# If the user didn't type anything in, use the fallback name
if not first_name:
    first_name = get_first_name(fallback_name)

print(f"Hi, {first_name}!")

See the docs for the typing module