1 test = "feng"
2 首字母大写
3 v = test.capitalize()
4 print(v)

1 v1 = test.casefold()
2 print(v1)
3 v2 = test.lower()
4 print(v2)

1 # 20 代指总长度
2 # *  空白未知填充，一个字符，可有可无
3 v = test.center(20,"中")
4 print(v)

>>>中中中中中中中中feng中中中中中中中中

1 test = "fengfeng"
2 v = test.count(‘en‘)
3 print(v)
4 
5 test = "fengfeng"
6 v = test.count(‘en‘,5,7)
7 print(v)

1 test = "feng"
2 v = test.endswith(‘en‘)
3 v = test.startswith(‘en‘)
4 print(v)

1 test = "feng"
2 #未找到 -1
3 v = test.find(‘en‘)
4 print(v)
5 
6 test = "feng"
7 v = test.index(‘feng‘)
8 print(v)

 1 test = ‘i am {name}, age {a}‘
 2 print(test)
 3 v = test.format(name=‘feng‘,a=19)
 4 print(v)
 5 
 6 test = ‘i am {0}, age {1}‘
 7 print(test)
 8 v = test.format(‘feng‘,19)
 9 print(v)
10 
11 #格式化，传入的值 {"name": ‘feng‘, "a": 19}
12 test = ‘i am {name}, age {a}‘
13 v1 = test.format(name=‘df‘,a=10)
14 v2 = test.format_map({"name": ‘feng‘, "a": 19})

1 test = "123"
2 v = test.isalnum()
3 print(v)