字符串增加
直接 +
name = 'de8ug'
city = 'beijing'
info = name + ' ' + city
info
'de8ug beijing'
% 占位符替换
'name: %s, place: %s'%(name,city)
'name: de8ug, place: beijing'
{}format 变量替换{} 或者 参数赋值
'name:{},place:{}'.format(name,city)
'name:de8ug,place:beijing'
'name:{nameA},place:{placeA}'.format(nameA=name,placeA=city)
'name:de8ug,place:beijing'
f-string
f'name:{name},place:{city}'
'name:de8ug,place:beijing'
' lilei said "where is han×××" '
或者 " lilei said 'where is han×××' " #双引号内加单引号或者单引号内加双引号
删除字符串
name = 'de8ug'
name = ''
name
''
字符串修改
name = 'de8ug'
name.upper() #大写
'DE8UG'
name.lower() #小写
'de8ug'
name.capitalize() #首字母大写
'De8ug'
name = "python is cool"
name.title() #标题大写
'Python Is Cool'
name.strip('python') #去掉python（开头和结尾的空格或者字符串去掉）
' is cool'
email = 'de8ug#foxmail.com'
email.replace('#','@') #email.replace(old,new)
'de8ug@foxmail.com'
email.split('#') #去除分隔符，变成列表
['de8ug', 'foxmail.com']
email.zfill(30)
'0000000000000de8ug#foxmail.com'
email.ljust(30,'8') #email.ljust(width.fillchar) 左对齐再填充
'de8ug#foxmail.com8888888888888'
email.rjust(20,'*') #右对齐再填充
'***de8ug#foxmail.com'
email.center(20,'*') #中间对齐再填充
'*de8ug#foxmail.com**'
字符串查
1.字符串.方法（）
'de8ug'.count('8')
1
name.isupper() #判断是否为大写
False
name.islower() #判断是否为小写
True
py = 'python is cool'
py.index('is') #查询在哪个位置
7
py.index('o')
4
py.find('is')
7
py.find('isaaa') #所有不存在为-1
-1
dir(py) #看有哪些方法可用
['__add__',
'__class__',
'__contains__',
'__delattr__',
'__dir__',
'__doc__',
'__eq__',
'__format__',
'__ge__',
'__getattribute__',
'__getitem__',
'__getnewargs__',
'__gt__',
'__hash__',
'__init__',
'__init_subclass__',
'__iter__',
'__le__',
'__len__',
'__lt__',
'__mod__',
'__mul__',
'__ne__',
'__new__',
'__reduce__',
'__reduce_ex__',
'__repr__',
'__rmod__',
'__rmul__',
'__setattr__',
'__sizeof__',
'__str__',
'__subclasshook__',
'capitalize',
'casefold',
'center',
'count',
'encode',
'endswith',
'expandtabs',
'find',
'format',
'format_map',
'index',
'isalnum',
'isalpha',
'isdecimal',
'isdigit',
'isidentifier',
'islower',
'isnumeric',
'isprintable',
'isspace',
'istitle',
'isupper',
'join',
'ljust',
'lower',
'lstrip',
'maketrans',
'partition',
'replace',
'rfind',
'rindex',
'rjust',
'rpartition',
'rsplit',
'rstrip',
'split',
'splitlines',
'startswith',
'strip',
'swapcase',
'title',
'translate',
'upper',
'zfill']
my_name =input('name: ')
name: de8ug
my_name
'de8ug '
len(my_name) #可以包含空格
7
type(my_name)
str
my_name.strip()
'de8ug'
len(my_name.strip())
5
切片查询
py = 'python2 python3 python4 python8'
py[3]
'h'
py[-2]
'n'
py[:6]
'python'
py.index('2')
6
py[:py.index('2')]
'python'
something = 'abcdefg1234567'
something[1:6:2] #索引1到6 步长为2
'bdf'
something[4:] #左边包括
'efg1234567'
something[:4] #右边不包括
'abcd'
something[4::4]
'e26'
something[something.index('e'):]
'efg1234567'
email = 'de8ug@foxmail.com'
email.split('@') #去除分隔符，变成列表
['de8ug', 'foxmail.com']
email.index('@')
5
email[:email.index('@')]
'de8ug'
email.find('@')
5
email[email.find('@')+1:] #左边包括
'foxmail.com'