capitalize()把字符串进行首字母大写:
test = 'drocess finished with exit code 0'
v = test.capitalize()
print(v)
输出:
Drocess finished with exit code 0
title()把字符串标题化(每个单词首字母大写)
upper()把每个字符转化为大写
lower()把每个字符转化为小写
test ='drocess finished with exit code 0 '
v1 = test.title()
print(v1)
输出:
Drocess Finished With Exit Code 0
swapcase()交换字母的大小写
test = 'Alex'
v = test.swapcase()
print(v)
istitle()判断字符串是否是标题(每个单词首字母大写)
isupper()判断字符串中的字母是否全是大写
islower()判断字符串中的字母是否全是小写
test ='Process finished with exit code 0 '
v1 = test.istitle()
print(v1)
v2 = test.title()
print(v2)
v3 = v2.istitle()
print(v3)
输出:
False
Process Finished With Exit Code 0
True
casefold()和lower()把字符串转换成小写,前者更倾向国际使用:
test = 'ALEX'
v1 = test.casefold()
print(v1)
v2 = test.lower()
print(v2)
输出:
alex
alex
center()设置字符串居中
ljust()设置字符串靠左
rjust()设置字符串靠右
20代表总宽度,*代表空白位置填充
test = 'Lex'
v3 = test.center(20,'*')
print(v3)
输出:
********Lex*********
count()寻找字符串中的子序列的个数,从第索引5-20内找
test = 'aLExgoog'
v3 = test.count('g',5,20)
print(v3)
输出:
1
encode()
decode()
endswith(),startswith(),字符串是否以子序列开始或结尾
test = 'aLExgoog'
v3 = test.endswith('g')
print(v3)
v2 = test.startswith('e')
print(v2)
输出:
True
False
find()从位置5-12查找字符串中的第一个子序列的位置,-1表示未找到
rfind()从位置12-5找字符串中的倒数第一个子序列的位置,-1表示未找到
test = 'Alexdgdagdfdsafdaf'
v = test.find("d",5,12)
print(v)
v2 = test.rfind('d',5,12)
print(v2)
输出:
6
11
format()格式化,将字符串中的占位符替换为指定的值,用变量或者索引
test = 'I am {name},age is {a}' #用变量name,a
v3 = test.format(name='malin',a=19)
print(v3)
输出:
I am malin,age is 19
test = 'I am {0},age is {1}' # 用索引
v3 = test.format('malin',19)
print(v3)
输出:
I am malin,age is 19
format_map()格式化,将字符串中的占位符替换为指定的值,用字典
test = 'I am {name},age is {a}'
v3 = test.format_map({'name':'malin','a':19})
print(v3)
输出:
I am malin,age is 19
isalnum()判断字符串的字符是否全是字母或中文或数字
test = '我是n9780'
v3 = test.isalnum()
print(v3)
输出:
True
isalpha()判断字符串的字符是否全是字母或者中文
test = 'L我是ling'
v3 = test.isalpha()
print(v3)
输出:
True
expandtabs()以长度20为单位(遇到制表符\t时补充空格到20)制作表格.
test = 'username\temail\tpasswd\nmalin\[email protected]\t123\t'
v3 = test.expandtabs(20)
print(v3)
isdecimal(),isdigit(),isnumeric判断字符串的字符是否全是数字
isdecimal()只能判断阿拉伯数字,比如2
isdigit还能判断符号数字,比如②
isnumeric还能判断中文数字,比如二
test = '二' #或test='②'
v1 = test.isdecimal()
v2 = test.isdigit()
v3 = test.isnumeric()
print(v1,v2,v3)
输出:
False False True
isidentifier()判断字符串是否是标识符
** 标识符:字母,数字,下划线,且第一个字符不能为数字**
test = '2fsaa_f123'
v1 = test.isidentifier()
print(v1)
输出:
False
isprintable()判断字符串的字符是否包含转义过的字符
test = '电饭锅\t'
v1 = test.isprintable()
print(v1)
输出:
False
isspace()判断字符串是否全是空格
test = ' '
v1 = test.isspace()
print(v1)
输出:
True
join()将字符串t加入到字符串test中的每一个字符之间
test ='你是风儿我是沙'
print(test)
t = '++++++'
v1 = t.join(test)
print(v1)
输出:
你是风儿我是沙
你++++++是++++++风++++++儿++++++我++++++是++++++沙
例2:
'.'.join(['ab', 'pq', 'rs']) -> 'ab.pq.rs'
lstrip()字符串左边依次去除匹配到的字符,直到不匹配
rstrip()字符串右边依次去除匹配到的字符,直到不匹配
strip()字符串两边依次去除匹配到的字符,直到不匹配
当没有参数时可去除空白部分
test ='abcdefg123'
v1 = test.lstrip('ae3b')
v2 = test.rstrip('ae3b')
v3 = test.strip('ae3b')
print(v1)
print(v2)
print(v3)
输出:
cdefg123
abcdefg12
cdefg12
maketrans()建立字符串对应表,translate()依照对应表翻译字符串.
test = 'abcdefghij'
test1 = '1234567890'
v = 'ldifgalfllif'
m = str.maketrans(test,test1)
print(v.translate(m))
输出:
l49671l6ll96
partition()从左边遇到的第一个参数把字符串分割成3部分,结果是一个元祖
test = 'www.baidu.com'
v = test.partition('.')
print(v)
输出:
(‘www’, ‘.’, ‘baidu.com’)
rpartition()从右边遇到的第一个参数把字符串分割成3部分,结果是一个元祖
test = 'www.baidu.com'
v = test.rpartition('.')
print(v)
输出:
(‘www.baidu’, ‘.’, ‘com’)
split()从左边开始用参数".“将字符串分割1次,参数”."不保留,不写1表示全部分割,结果是一个列表
test = 'www.baidu.com'
v = test.split('.',1)
print(v)
v2 = test.split('.')
print(v2)
输出:
[‘www’, ‘baidu.com’]
[‘www’, ‘baidu’, ‘com’]
rsplit()从右边开始用参数s将字符串分割3次,参数s不保留,不写3表示全部分割
test = 'www.baidu.com'
v = test.rsplit('.',1)
print(v)
输出:
[‘www.baidu’, ‘com’]
replace()把字符串中的字符s替换成a,共替换3次
test = 'sssssbbbbbb'
v = test.replace('s','a',3)
print(v)
输出:
aaassbbbbbb