Python筆記 之 str模塊

01 將指定對象轉為字符串

str(object=’’) -> str

st01 = 1000
st = str(st01)

02 創建字符串

str(bytes_or_buffer[, encoding[, errors]]) -> str

st02 = 'chengdu'
st = str(b'abc',encoding='utf-8')

03 字符串首字符大寫

capitalize(self, /)

st03 = 'henan is very good'
st = st03.capitalize()

04 將字符串轉換為便於比較格式

casefold(self, /)

st04 = 'ThewaetherIS Very HOt'
st = st04.casefold()

05 字符串居中並填充

center(self, width, fillchar=’ ', /)

st05 = 'Welcome'
st = st05.center(20,'-')

06 查詢子字符串在字符串中出現的次數，可以指定起止位置

S.count(sub[, start[, end]]) -> int

st06 = 'abcdefghijkabcdefghijk'
st = st06.count('ka',1,-1)

07 將字符串按指定編碼格式轉為bytes類型

encode(self, /, encoding=‘utf-8’, errors=‘strict’)

st07 = '河南鄭州'
st = st07.encode('utf-8')

08 判斷字符串指定位置是否為子字符串

S.endswith(suffix[, start[, end]]) -> bool

st08 = 'Welcome'
st = st08.endswith('come',3)

09 將字符串中所有的\t擴展到指定位數長度

expandtabs(self, /, tabsize=8)

st09 = 'Welcome\tto\tBeiJing\t'
st = st09.expandtabs(4)

10 在字符串指定起止未知查找子字符串返回子字符串首次出現首字母的位置索引

S.find(sub[, start[, end]]) -> int

st10 = 'abcdefghijkabcdefghijk'
st = st10.find('abc',10,-1)

11 字符串格式化

S.format(*args, **kwargs) -> str

st11= '{},你好，歡迎來到{}.'
st = st11.format('韓梅梅','北京')

st11 = '{1},你好，歡迎來到{0}.'
st = st11.format('北京','韓梅梅')

12 按關鍵字格式化字符串

S.format_map(mapping) -> str

st11 = '{name},你好，歡迎來到{city}.'
st = st11.format(city='北京',name='韓梅梅')

13 獲取子字符串首次出現在指定起止未知的首字母的索引

S.index(sub[, start[, end]]) -> int

st13 = '韓梅梅,你好，歡迎來到北京.'
st = st13.index('歡迎',1,-1)

14 判斷字符串是否全部由字母(保護漢字)和數字組成

isalnum(self, /)

st14 = '12345a和'
st = st14.isalnum()

15 判斷字符串是否全部由字母(保護漢字)

isalpha(self, /)

st15 = 'aaaa和'
st = st15.isalpha()

16 判斷字符串是否全由ascii碼組成

isascii(self, /)

st16 = '北京'
st = st16.isascii()

17 判斷字符串是否全由數字組成

isdecimal(self, /)

st17 = '1234.1'
st = st17.isdecimal()

18 判斷字符串是否是數字字符串，不支持小數點

isdigit(self, /)

st18 = '1235'
st = st18.isdigit()

19 判斷字符串是否為python保留字

isidentifier(self, /)

st19 = 'def'
st = st19.isidentifier()

20 判斷字符串是否全部小寫

islower(self, /)

st20 = 'beijing'
st = st20.islower()

21 判斷字符串是否是數字字符串，不支持小數點

isnumeric(self, /)

st21 = '1212'
st = st21.isnumeric()

22 判斷字符串是不是一個可打印類型

isprintable(self, /)

st22 = str(set((1,2,3)))
st = st22.isprintable()

23 判斷字符串是否為空字符串

isspace(self, /)

st23 = ' '
st = st23.isspace()

24 判斷字符串是否是標題類型

istitle(self, /)

st24 = 'The Title Is Henan'
st = st24.istitle()

25 判斷字符串是否大寫

isupper(self, /)

st25 = 'HELLOq'
st = st25.isupper()

26 將一個可迭代對象用指定字符串連接起來

st26 = ('www','baidu','com')
st = '.'.join(st26)

27 指定字符串左對齊並顯示指定的位數不夠的位數用指定的字符串填充

ljust(self, width, fillchar=’ ', /)

st27 = 'Hello'
st = st27.ljust(20,'-')

28 將指定字符串小寫

lower(self, /)

st28 = "Hello 韓梅梅，Welcome"
st = st28.lower()

29 移除字符串左邊的自定字符串

lstrip(self, chars=None, /)

st29 = ' hello welcome -'
st = st29.lstrip('-')

30 從字符串左側查找指定分隔符，返回分隔符前、分隔符、分隔符後三部分的元祖

partition(self, sep, /)

st30 = 'hello,韓梅梅 welcome'
st = st30.partition(',')

31 如果字符串以指定子串開頭返回去除子串的部分，否則返回原字符串

removeprefix(self, prefix, /)

st31 = 'hello,韓梅梅 welcome'
st = st31.removeprefix('hello')

32 如果字符串以指定子串結尾返回去除子串的部分，否則返回原字符串

removesuffix(self, suffix, /)

st32 = 'hello,韓梅梅 welcome'
st = st32.removesuffix('welcome')

33 使用new子串替代字符串中的old子串

replace(self, old, new, count=-1, /)

st33 = 'hello,韓梅梅 welcome'
st = st33.replace('梅梅','雪雪')

34 返回字符串中指定子串的最大索引

S.rfind(sub[, start[, end]]) -> int

st34 = 'abcdefghijkabcdefghijk'
st = st34.rfind('d',1,-1)

35 返回字符串中指定子串的最大索引

S.rindex(sub[, start[, end]]) -> int

st35 = 'abcdefghijkabcdefghijk'
st = st35.rindex('d',1,-1)

36 使字符串右對齊並顯示指定長度，如果長度不夠使用指定字符串填充

rjust(self, width, fillchar=’ ', /)

st36 = 'rjust with tab'
st = st36.rjust(30,'-')

37 從字符串右側查找分隔符，使用分隔符將字符串分割為分割前、分隔符、分割後三部分的元祖

rpartition(self, sep, /)

st37 = '河南省信陽'
st = st37.rpartition('省')

38 用指定字符串從右側分割字符串，返回分割後的字符串列表，可指定分割長度

rsplit(self, /, sep=None, maxsplit=-1)

st38 = 'hello,Lee,welcome,to,china'
st = st38.rsplit(',',2)

39 去除字符串右側指定子串

rstrip(self, chars=None, /)

st39 = 'welcome --'
st = st39.rstrip('-')

40 用指定字符串從左側分割字符串，返回分割後的字符串列表，可指定分割長度

split(self, /, sep=None, maxsplit=-1)

st40 = 'hello,Lee,welcome,to,china'
st = st40.split(',',2)

41 用換行符分割字符串,可指定顯示換行符

splitlines(self, /, keepends=False)

st41 = 'Hello Lee \n Welcom to china'
st = st41.splitlines()

42 判斷字符串是否已子串開頭

S.startswith(prefix[, start[, end]]) -> bool

st42 = 'helloleewelcometochina'
st = st42.startswith('hello')

43 返回去除字符串左右指定子串後的字符串

strip(self, chars=None, /)

st43 = ' helloleewelcometochina '
st = st43.strip(' ')

44 是字符串中大小寫字符互換

swapcase(self, /)

st44 = 'Hello Lee,welcome to china'
st = st44.swapcase()

45 將字符串轉為title類型字符串

title(self, /)

st45 = 'the title is test'
st = st45.title()

46 通過譯碼表對字符串中的字符進行一對一轉換

translate(self, table, /)

st46 = 'ETC 快E速通過'
ss = str.maketrans('ETC','電子記')
st = st46.translate(ss)

47 將字符串所有字符大寫

upper(self, /)

st47 = 'the title is test'
st = st47.upper()

48 用0填充數字字符串的坐標構成指定長度

zfill(self, width, /)

st48 = '121.88'
st = st48.zfill(12)

49 返回一個永遠translate的譯碼表

maketrans(…)

st49 = str.maketrans('abc','ABC')
st = st49

50 字符串反轉

st50 = 'chengdu'
st = st50[::-1]

print(st)