1、字符串首字母大写
>>> name = "xiaoming"
>>> print(name.capitalize()) //capitalize方法可以使字符串首字母大写
Xiaoming
2、统计字符串中字符的个数
>>> name = "xiaoming"
>>> print(name.count("i"))
2
3、重复打印某个字符
>>> print(name.center(20,"-")) //总共有20个字符，把"xiaoming"放在中间
------xiaoming------
4、判断字符串以什么结尾
>>> name = "xiaoming"
>>> print(name.endswith("ng"))
True
5、根据字符找索引位置
>>> name = "My name is Xiaoming"
>>> print(name.find("is")) //find只打印查找到的字符的开头字母的位置
8
>>> print(name[name.find("is"):]) //字符串也支持切片
is Xiaoming
6、字符串格式化输出
>>> name = "My name is {name} and I am {year} years old."
>>> print(name.format(name="Xiaoming",year=20)) //format格式化输出
My name is Xiaoming and I am 20 years old.
>>> print(name.format_map( {"name":"Xiaoming","year":25} )) //format_map可以以字典的格式进行传输
My name is Xiaoming and I am 25 years old.
7、判断字符串是不是纯英文字符组成
>>> name = "abc"
>>> print(name.isalpha())
True
>>> name = "ab12"
>>> print(name.isalpha())
False
8、判断数字是不是整数
>>> print("aa".isdigit())
False
>>> print("11".isdigit())
True
>>> print("11.2".isdigit())
False
9、判断字符串是不是小写
>>> name = "abc"
>>> print(name.islower())
True
>>> name = "My"
>>> print(name.islower())
False
10、判断字符串中的字符开头是不是大写字母
>>> name = "my name"
>>> print(name.istitle())
False
>>> name = "My Name"
>>> print(name.istitle())
True
11、判断字符串是不是全是大写字母
>>> name = "MY NAME"
>>> print(name.isupper())
True
12、join的简单使用
>>> print("".join(["1","2","3"]))
123
>>> print("+".join(["1","2","3"]))
1+2+3
13、ljust()和rjust()的使用
>>> name
'MY NAME'
>>> print(name.ljust(20,"*")) //注意：是整个字符串共长20，"MY NAME"共长7，所以"*"只有13个
MY NAME*************
>>> print(name.rjust(20,"*"))
*************MY NAME
14、字符串的大小写转换
>>> name
'MY NAME'
>>> print(name.lower()) //lower是把大写变成小写
my name
>>> print(name.upper()) //upper是把小写转换为大写
MY NAME
15、去除字符串两头的回车或者空格
>>> print("\nMy name")
My name
>>> print("\nMy name".lstrip()) //lstrip为去除字符串左边的空格或回车
My name
>>> print("My name\n")
My name
>>> print("My name\n".rstrip()) //rstrip为去除字符串右边的空格或回车
My name
>>> print("\nMy name\n".strip()) //strip为去除两头的空格或回车
My name
16、字符的替换
>>> print("abca".replace("a","L")) //默认为全部替换
LbcL
>>> print("abca".replace("a","L",1)) //可以指定
Lbca
17、字符串分割成列表
>>> print("My name is Xiaoming".split()) //默认为空格
['My', 'name', 'is', 'Xiaoming']
>>> print("My name is Xiaoming".split("i")) //可以指定分隔符
['My name ', 's X', 'aom', 'ng']
18、swapcase，把字符串中的小写转大写，大写转小写
>>> print("My name is".swapcase())
mY NAME IS