①所有字母都转换为大写

# -*- coding:utf-8 -*-

if __name__ == "__main__":
a = 'hello, world!'
print(a.upper())输出：

HELLO, WORLD!

②所有字母都转换为小写

# -*- coding:utf-8 -*-

if __name__ == "__main__":
a = 'HELLO, WORLD!'
print(a.lower())输出：

hello, world!

③首字母转换成大写， 其余转换成小写

# -*- coding:utf-8 -*-

if __name__ == "__main__":
a = 'HELLO, WORLD!'
print(a.capitalize())输出：

Hello, world!

④所有单词的首字母转换成大写， 其余转换成小写

# -*- coding:utf-8 -*-

if __name__ == "__main__":
a = 'HELLO, WORLD!'
print(a.title())输出：

Hello, World!

⑤判断所有字母都为大写

# -*- coding:utf-8 -*-

if __name__ == "__main__":
a = 'HELLO, WORLD!'
print(a.isupper())

b = 'hello, world!'
print(b.isupper())输出：

True
False

⑥判断所有字母都为小写

# -*- coding:utf-8 -*-

if __name__ == "__main__":
a = 'HELLO, WORLD!'
print(a.islower())

b = 'hello, world!'
print(b.islower())输出：

False
True

⑦判断所有单词的首字母为大写

# -*- coding:utf-8 -*-

if __name__ == "__main__":
a = 'HELLO, WORLD!'
print(a.istitle())

b = 'hello, world!'
print(b.istitle())

c = 'Hello, World!'
print(c.istitle())输出：

False
False
True

以上这篇Python 字符串大小写转换的简单实例就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持。