字符串类型转换
int()
将符合整数格式的字符串转换为整数。
int("589") == 589int(4.56) == 4 float()
将符合浮点数格式的字符串转换为浮点数。
float("45.6") == 45.6float(5) == 5.0 str()
将整数和浮点数转换为字符串。
str(567) == '567'str(45.6) == '45.6'str(0xcc) == '204'
字符串大小写转换
lower()
大写全转换小写
>>> 'ABC,ABC,ABC,ABC,ABC,ABC,ABC'.lower()abc,abc,abc,abc,abc,abc,abc
upper()
小写全转换大写
>>> 'abc,abc,abc,abc,abc,abc,abc'.upper()ABC,ABC,ABC,ABC,ABC,ABC,ABC
title()
单词首字母转换为大写
>>> 'abc,abc,abc,abc,abc,abc,abc'.title()Abc,Abc,Abc,Abc,Abc,Abc,Abc
capitalize()
语句首字母转换为大写
>>> 'abc,abc,abc,abc,abc,abc,abc'.capitalize()Abc,abc,abc,abc,abc,abc,abc
swapcase()
大小写互换
>>> 'Abc,Abc,Abc,Abc,Abc,Abc,Abc'.swapcase()aBC,aBC,aBC,aBC,aBC,aBC,aBC
查找统计
find()
显示特定字符串的位置序列号，无查找到返回值【-1】
>>> '1,2,3,4,5,6,7,8,9,10'.find('4')6>>> 'this is string '. find('is')8 index()
索引，字符串位置并输出序列号，无索引到会报错
>>> '1,2,3,4,5,6,7,8,9,10'.index('4')6 count()
统计字符串出现次数
>>> 'abc,abc,abc,abc,abc,abc,abc'.count('a')7 len()
统计字符串长度
>>> print(len('abc,abc,abc,abc,abc,abc,abc'))27 匹配判断
in()
判断字符串包含关系
>>> a = "123456789">>> b = "2" in a>>> print(b)True
startswith()
匹配开始字符串是否一致
>>> 'This is test'.startswith('This')True endswith()
匹配结束字符串是否一致
>>> 'This is test'.endswith('test')True isalnum()
判断字符串是否只包含数字和字母
>>> '123@test.com'.isalnum()False
isalpha()
判断字符串是否只包含字母
>>> 'This is test'.isalpha()False>>> 'Thisistest'.isalpha()True
isdecimal()
判断字符串是否只包含数字
>>> '123456789'.isdecimal()True
匹配替换
切片取字符串范围
取字符串前四位
a = "123456789"print(a[0:4])
去除字符串后四位
a = "123456789"print(a[:-4])
replace()
匹配项替换
>>> '1,2,3,4,5,6,7,8,8,10'.replace('6','A')'1,2,3,4,5,A,7,8,8,10' translate()
匹配项多项替换
>>> from string import maketrans>>> intab = "acg">>> outtab = "123">>> trantab = maketrans(intab, outtab)>>> str = "a,b,c,d,e,f,g";>>> print str.translate(trantab);1,b,2,d,e,f,3
字符串规整
join()
添加连接符
>>> a = ['1','2','3','4','5','6','7','8','9','10']>>> b = '+'>>> b.join(a)'1+2+3+4+5+6+7+8+9+10'
或
>>> ('+').join(['1','2','3','4','5','6','7','8','9','10'])'1+2+3+4+5+6+7+8+9+10' split()
去除连接符
>>> '1+2+3+4+5+6+7+8+9+10'.split('+')['1','2','3','4','5','6','7','8','9','10'] strip()
去除两侧多余显示字符(默认去除空格)
>>> ' this is test!!! '.strip()'!!!this is test!!!'
>>> 'this is test!!!'.strip('!')'this is test' lstrip()
去除开始多余显示字符(默认去除空格)
>>> '!!!this is test!!!'.lstrip('!')'this is test!!!' rstrip()
去除结束多余显示字符(默认去除空格)
>>> '!!!this is test!!!'.rstrip('!')'!!!this is test' format()
位置序列号格式化参数
>>> a = "可爱的{0},最喜欢在{1},{2}！！！">>> b = a.format("小猪","河边","抓泥鳅")>>> print(b)可爱的小猪,最喜欢在河边,抓泥鳅！！！ 字符串填充位置调整
字符串居中，靠左，靠右
test = "字符"v1 = test.center(20,"*")print(v1)v2 = test.ljust(20,"*")print(v2)v3 = test.rjust(20,"*")print(v3)
*********字符*********字符************************************字符
expandtabs()
制表符
>>> a = "user\tenail\tpasswd\nxiaoming\t1234@test.com\t123">>> print(a.expandtabs(20))
user enail passwdxiaoming 1234@test.com 123
去重
x=[1,2,3,1]print(list(set(x)))