字符串的常用操作

name = "my \tname is {name} and i am {year} old"
print(name.capitalize())#首字母大写
My     name is {name} and i am {year} old

name = "my \tname is {name} and i am {year} old"
print(name.count("a"))#字符串里面包含几个"a"
5

name = "my \tname is {name} and i am {year} old"
print(name.center(50,"-"))#打印50个字符如果不够用-补全
------my     name is {name} and i am {year} old------

name = "my \tname is {name} and i am {year} old"
print(name.endswith("ex"))#判断字符串是以什么结尾
False

name = "my \tname is {name} and i am {year} old"
print(name.expandtabs(tabsize=30))#将tab转换成多少个空格
my                            name is {name} and i am {year} old

name = "my \tname is {name} and i am {year} old"
print(name[name.find("name"):])#字符串name所在的索引值，同时可以用来切片
name is {name} and i am {year} old

name = "my name is {name} and i am {year} old"
print(name.format(name=‘alex‘,year=23))#格式化输出
my     name is alex and i am 23 old

name = "my name is {name} and i am {year} old"
print(name.format_map({‘name‘:‘alex‘,‘year‘:12}))#如果格式化，导入的是字典，可以用format_map方法，结果跟format一样。
my     name is alex and i am 12 old

name = ""
print(name.isalnum())#如果 name 至少有一个字符并且所有字符都是字母或数字则返回 True,否则返回 False
False
name = "ads12"
print(name.isalnum())#如果 name 至少有一个字符并且所有字符都是字母或数字则返回 True,否则返回 False
True

name = "my name is big long"
print(name.isdigit())#判断字符串只包含数字则返回 True 否则返回 False
False
print("22".isdigit())#判断字符串只包含数字则返回 True 否则返回 False
True

print(‘a‘.isidentifier())#判断是不是一个合法的标识符
True

print("33".isspace())#判断是不是空格
False
print(" ".isspace())#判断是不是空格
True

print(‘My Name Is ‘.istitle())#判断字符串首写字母是不是大写

>>> print(‘+‘.join([‘1‘,‘2‘,‘3‘]))#用于将序列中的元素以指定的字符连接生成一个新的字符串。
1+2+3