Sentence capitalizer in python

Example:

def f1 (string1: str):
    sentences = string1.split(". ")
    sentences2 = [sentence[0].capitalize() + sentence[1:] for sentence in sentences]
    string2 = '. '.join(sentences2)
    return string2
print (f1("hello. my name is Joe. what is your name?"))

Output:

Hello. My name is Joe. What is your name?

Example:

import re
def sentence_case(text):    
     
    sentences = re.findall('[^.!?]+[.!?](?:\s|\Z)', text)

    sentences = [x[0].upper() + x[1:] for x in sentences]
   
    return ''.join(sentences)

print(sentence_case("hEllo. my name is Joe. what is your name?"))

Output:

HEllo. My name is Joe. What is your name?