python中的 upper() 、lower()、capitalize()、title()方法

upper()字符串中字母由小写变为大写
lower()字符串中字母由大写变为小写
capitalize()字符串中字母首字母大写其余小写
title()字符串中字母每个单词的首字母大写其余小写

1 a = "hello"
2 b = "WORLD"
3 c = "hello"
4 d = "hello world"
5 a1 = a.upper()
6 b1 = b.lower()
7 c1 = c.capitalize()
8 d1 = d.title()
9 print(a1)
10 print(b1)
11 print(c1)
12 print(d1)
复制代码
输出结果：

HELLO
world
Hello
Hello World