Is it possible in Python to write a function that does not explicitly return any values?

Yes, in Python, you can write a function that explicitly does not return any values. If a function lacks a return statement or uses it without a value, the function returns a special value None.

Example:

def foo():
    print("Hello")

result = foo()  # Will print Hello
print(result)  # Will print None

Thus, the function does not explicitly return any values, but implicitly returns None.