Python字符串字母大小寫變換

說明：

字符串就是一系列字符，在Python中用引號括起來的都是字符串，引號可以是單引號，也可以是雙引號，比如：“This is a book.”  ‘This is an apple.’

接下來簡單說明下關於字符串大小寫的變換。

 

操作：

casefold() 所有字母小寫
lower() 所有字母小寫
upper() 所有字母大寫
capitalize() 所有字母小寫
title() 所有首字母大寫，其余字母小寫
swapcase() 大小寫字母替換
這幾個方法都是生成新的字符串，不對原字符串內容進行修改。

demo = 'tHis iS a GOod boOK.'
print(demo.casefold())
print(demo.lower())
print(demo.upper())
print(demo.capitalize())
print(demo.title())
print(demo.swapcase())

　　

輸出：

this is a good book.
this is a good book.
THIS IS A GOOD BOOK.
This is a good book.
This Is A Good Book.
ThIS Is A goOD BOok.