How to Capitalize Sentences in Python: Simple Code Solutions

1. Introduction

Earlier in a Python community a user asked how to convert a string such as "hello. my name is Joe. what is your name?" into a version where each sentence starts with an uppercase letter, e.g., "Hello. My name is Joe. What is your name?".

2. Implementation

One solution splits the text by periods, capitalizes the first character of each fragment, and joins them back with periods.

# 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(".")]))

The code produces the expected capitalized output.

A second, more robust solution also handles exclamation marks and question marks.

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)

This approach first inserts line breaks after each punctuation mark, then capitalizes the first character of each line, providing stronger handling of typical English sentence terminators.

3. Conclusion

The article presents two straightforward methods for capitalizing the first letter of each sentence in an English text using Python, encouraging readers to experiment with alternative solutions and share their own approaches.