How to Automatically Capitalize Sentences in Python Strings

1. Introduction

Hello, I am PiPi. A follower asked how to process a string so that each sentence begins with a capital letter.

2. Problem Statement

Given an input string such as "hello. my name is Joe. what is your name?", the goal is to return a copy where the first character of each sentence is uppercase, e.g., "Hello. My name is Joe. What is your name?".

3. Implementation

First solution (splits by period and capitalizes the first character of each fragment):

# coding:utf-8
# @Time : 2022/5/4 10:46
# @Author: PiPi
text = "hello.my name is Joe.what is your name?"
print(".".join([i[:1].upper() + i[1:] for i in text.split(".")]))

Running the code produces the expected capitalized result.

Second solution (handles period, exclamation mark, and question mark for greater robustness):

s = 'i love Python.i love Python!i love Python,and do you love C++?'
st = s.replace('.', '.
').replace('!', '!
').replace('?', '?
')
result = ''.join(k[0].upper()+k[1:] for k in st.split('
')[:-1])
print(result)

The output correctly capitalizes each sentence regardless of the terminating punctuation.

4. Conclusion

The article presented two straightforward Python methods to capitalize the first letter of every sentence in an English text, covering common sentence terminators and providing ready-to-use code snippets.