字符串作为平时使用最多的数据类型，其常用的操作我们还是很有必要熟记于心的，本文整理了多种字符串的操作的案例，还是非常用心，全文篇幅巨长，建议收藏再看

test = "Python Programming"print("String: ", test) # First one characterfirst_character = test[:1]print("First Character: ", first_character) # Last one characterlast_character = test[-1:]print("Last Character: ", last_character) # Everything except the first one characterexcept_first = test[1:]print("Except First Char.: ", except_first) # Everything except the last one characterexcept_last = test[:-1]print("Except First Char.: ", except_last) # Everything between first and last two characterbetween_two = test[2:-2]print("Between two character: ", between_two) # Skip one characterskip_one = test[0:18:2] # [start:stop:step]print("Skip one character: ", skip_one) # Reverse Stringreverse_str = test[::-1]print("Reverse String: ", reverse_str)

Output:

String: Python ProgrammingFirst Character: PLast Character: gExcept First Char.: ython ProgrammingExcept First Char.: Python ProgramminBetween two character: thon ProgrammiSkip one character: Pto rgamnReverse String: gnimmargorP nohtyP检查字符串是否为空

import refrom collections import Counter sentence = 'Canada is located in the northern part of North America'# Example Icounter = len(re.findall("a", sentence))print(counter) # Example IIcounter = sentence.count('a')print(counter) # Example IIIcounter = Counter(sentence)print(counter['a'])

Output:

EmptyEmptyEmpty计算字符串中字符出现次数的多种方法

import refrom collections import Counter sentence = 'Canada is located in the northern part of North America'# Example Icounter = len(re.findall("a", sentence))print(counter) # Example IIcounter = sentence.count('a')print(counter) # Example IIIcounter = Counter(sentence)print(counter['a'])

Output:

# String to Floatfloat_string = "254.2511"print(type(float_string)) string_to_float = float(float_string)print(type(string_to_float)) # String to Integerint_string = "254"print(type(int_string)) string_to_int = int(int_string)print(type(string_to_int)) # String to Booleanbool_string = "True"print(type(bool_string)) string_to_bool = bool(bool_string)print(type(string_to_bool))

Output:

class 'str'class 'float>class 'str'class 'int'class 'str'class 'bool'向字符串填充或添加零的不同方法

num = 7 print('{0:0>5d}'.format(num)) # leftprint('{0:0<5d}'.format(num)) # right print('{:05d}'.format(num)) print("%0*d" % (5, num))print(format(num, "05d")) temp = 'test'print(temp.rjust(10, '0'))print(temp.ljust(10, '0'))

Output:

0000770000000070000700007000000testtest000000去掉字符串中的 space 字符

string_var = " \t a string example\n\t\r "print(string_var) string_var = string_var.lstrip() # trim white space from leftprint(string_var) string_var = " \t a string example\t "string_var = string_var.rstrip() # trim white space from rightprint(string_var) string_var = " \t a string example\t "string_var = string_var.strip() # trim white space from both sideprint(string_var)

Output:

a string example a string example a string examplea string example生成N个字符的随机字符串

import stringimport random def string_generator(size): chars = string.ascii_uppercase + string.ascii_lowercase return ''.join(random.choice(chars) for _ in range(size)) def string_num_generator(size): chars = string.ascii_lowercase + string.digits return ''.join(random.choice(chars) for _ in range(size)) # Random Stringtest = string_generator(10)print(test) # Random String and Numbertest = string_num_generator(15)print(test)

Output:

acpPTojXetqmpah72cjb83eqd以不同的方式反转字符串

test_string = 'Python Programming' string_reversed = test_string[-1::-1]print(string_reversed) string_reversed = test_string[::-1]print(string_reversed) # String reverse logicallydef string_reverse(text): r_text = '' index = len(text) - 1 while index >= 0: r_text += text[index] index -= 1 return r_text print(string_reverse(test_string))

Output:

gnimmargorP nohtyPgnimmargorP nohtyPgnimmargorP nohtyP将 Camel Case 转换为 Snake Case 并更改给定字符串中特定字符的大小写

import re def convert(oldstring): s1 = re.sub('(.)([A-Z][a-z]+)', r'\1_\2', oldstring) return re.sub('([a-z0-9])([A-Z])', r'\1_\2', s1).lower() # Camel Case to Snake Caseprint(convert('CamelCase'))print(convert('CamelCamelCase'))print(convert('getHTTPResponseCode'))print(convert('get2HTTPResponseCode')) # Change Case of a particular charactertext = "python programming"result = text[:1].upper() + text[1:7].lower() \ + text[7:8].upper() + text[8:].lower()print(result) text = "Kilometer"print(text.lower()) old_string = "hello python"new_string = old_string.capitalize()print(new_string) old_string = "Hello Python"new_string = old_string.swapcase()print(new_string)

Output:

camel_casecamel_camel_caseget_http_response_codeget2_http_response_codePython ProgrammingkilometerHello pythonhELLO pYTHON检查给定的字符串是否是 Python 中的回文字符串

import re Continue = 1Quit = 2 def main(): choice = 0 while choice != Quit: # Display the menu. display_menu() # Constant to assume string is Palindrome is_palindrome = True # Get the user's choice. choice = int(input('\nEnter your choice: ')) # Perform the selected action. if choice == Continue: line = input("\nEnter a string: ") str_lower = re.sub("[^a-z0-9]", "", line.lower()) for i in range(0, len(str_lower)//2): if str_lower[i] != str_lower[len(str_lower) - i - 1]: is_palindrome = False if is_palindrome: print(line, "is a palindrome") else: print(line, "is not a palindrome") else: print('Thank You.') def display_menu(): print('\n*******MENU*******') print('1) Continue') print('2) Quit') main()

Output:

*******MENU*******1) Continue2) Quit Enter your choice: 1 Enter a string: A dog! A panic in a pagoda!A dog! A panic in a pagoda! is a palindrome *******MENU*******1) Continue2) Quit Enter your choice: 1 Enter a string: CivicCivic is a palindrome *******MENU*******1) Continue2) Quit Enter your choice: 1 Enter a string: Python vs JavaPython vs Java is not a palindrome *******MENU*******1) Continue2) Quit Enter your choice: 2Thank You.检查字符串是否以列表中的一个字符串结尾

str_list = ['aaa', 'bbb', 'ccc', 'ddd'] # list of itemsstr_test = 'testccc' # string need to test for str_item in str_list: if str_test.endswith(str_item): print("found") break # loop ends when result found else: print("not found")

Output:

not foundnot foundfound在字符串中应用查找模式

import res1 = 'abccba's2 = 'abcabc's3 = 'canadajapanuaeuaejapancanada'p = '123321'def match(s, p): nr = {} regex = [] for c in p: if c not in nr: regex.append('(.+)') nr[c] = len(nr) + 1 else: regex.append('\\%d' % nr[c]) return bool(re.match(''.join(regex) + '$', s))print(match(s1, p))print(match(s2, p))print(match(s3, p))

Output:

TrueFalseTrue如果是 Python 中的反斜杠，则删除最后一个字符

x = 'Canada\\'print(x.rstrip('\\'))

Output:

Canada在Python中拆分字符串而不丢失拆分字符

import restring = 'canada-japan-india'print(re.split(r'(\-)', string))

Output:

['canada', '-', 'japan', '-', 'india']从字符串 Python 中提取大写和小写字符

string = "asdfHRbySFss"uppers = [l for l in string if l.isupper()]print (''.join(uppers))lowers = [l for l in string if l.islower()]print (''.join(lowers))

Output:

HRSFasdfbyss如何在 Python 中比较字符串的索引是否相等

myString = 'AAABBB'for idx, char in enumerate(myString, ): if idx + 1 == len(myString): break if char == myString[idx + 1]: print(idx, char, myString[idx + 1])

Output:

0 A A1 A A3 B B4 B B在每个第 4 个字符上添加空格

string = 'Test5412Test8745Test'print([string[i:i + 4] for i in range(0, len(string), 4)])

Output:

['Test', '5412', 'Test', '8745', 'Test']在 Python 中以多行方式连接字符串

str1 = "This is a demo string"str2 = "This is another demo string"strz = ("This is a line\n" + str1 + "\n" + "This is line 2\n" + str2 + "\n" + "This is line 3\n")print(strz)

Output:

This is a lineThis is a demo stringThis is line 2This is another demo stringThis is line 3在 Python 中将多个变量附加到列表中

volumeA = 100volumeB = 20volumeC = 10vol1 = []vol2 = []vol1.extend((volumeA, volumeB, volumeC))vol2 += [val for name, val in globals().items() if name.startswith('volume')]print(vol1)print(vol2)

Output:

[100, 20, 10][100, 20, 10]将字符串拆分为 Python 中的字符列表

s = 'canada'l = list(s)print(l)

Output:

['c', 'a', 'n', 'a', 'd', 'a']如何在 Python 中小写字符串

text = ['Canada', 'JAPAN']text = [txt.lower() for txt in text]print(text)

Output:

['canada', 'japan']通过多个标点符号分割字符串

import res = 'a,b,c d!e.f\ncanada\tjapan&germany' l = re.split('[?.,\n\t&! ]', s) for i in l: print(i)

Output:

abcdefcanadajapangermanyPython 字符串填充

lines_of_text = [ (123, 5487, 'Testing', 'Billy', 'Jones'), (12345, 100, 'Test', 'John M', 'Smith')]for mytuple in lines_of_text: name = '{}, {}'.format(mytuple[4], mytuple[3]) value = '$' + str(mytuple[1]) print('{name:<20} {id:>8} {test:<12} {value:>8}'.format( name=name, id=mytuple[0], test=mytuple[2], value=value) )

Output:

Jones, Billy 123 Testing $5487Smith, John M 12345 Test $100在 Python 中检查两个字符串是否包含相同的字符

str1 = 'caars'str2 = 'rats'str3 = 'racs'print(set(str1)==set(str2))print(set(str1)==set(str3))

Output:

FalseTrue在 Python 中查找给定字符串中的整个单词

def contains_word(s, w): return (' ' + w + ' ') in (' ' + s + ' ')result = contains_word('those who seek shall find', 'find')print(result)result = contains_word('those who seek shall find', 'finds')print(result)

Output:

TrueFalse查找所有出现的子字符串

import reaString = 'this is a string where the substring "is" is repeated several times'print([(a.start(), a.end()) for a in list(re.finditer('is', aString))])

Output:

[(2, 4), (5, 7), (38, 40), (42, 44)]在 Python 中去除所有开头在Python中的正斜杠上拆分字符串和结尾标点符号

from string import punctuations = '.$958-5-Canada,#'print(s.strip(punctuation))

Output:

958-5-Canada用 Python 中的正斜杠上拆分字符串

s = 'canada/japan/australia'l = s.split('/') print(l)

Output:

['canada', 'japan', 'australia']根据 Python 中的索引位置将字符串大写

def capitalize(s, ind): split_s = list(s) for i in ind: try: split_s[i] = split_s[i].upper() except IndexError: print('Index out of range : ', i) return "".join(split_s)print(capitalize("abracadabra", [2, 6, 9, 10, 50]))

Output:

Index out of range : 50abRacaDabRA检查字符串中的所有字符是否都是Python中的数字

a = "1000"x = a.isdigit()print(x)b = "A1000"x = b.isdigit()print(x)

Output:

TrueFalse为什么使用'=='或'is'比较字符串有时会产生不同的结果

a = 'canada'b = ''.join(['ca', 'na', 'da'])print(a == b)print(a is b)a = [1, 2, 3]b = [1, 2, 3]print(a == b)print(a is b)c = bprint(c is b)

Output:

TrueFalseTrueFalseTrue如何在 Python 中为字符串添加 X 个空格

print('canada'.ljust(10) + 'india'.ljust(20) + 'japan')

Output:

canada india japan如何在Python中替换字符串中的特定字符串实例

def nth_replace(str,search,repl,index): split = str.split(search,index+1) if len(split)<=index+1: return str return search.join(split[:-1])+repl+split[-1]str1 = "caars caars caars"str2 = nth_replace(str1, 'aa', 'a', 1)print(str2)

Output:

caars cars caars如何连接两个变量，一个是字符串，另一个是 Python 中的 int

int1 = 10str1 = 'test'print(str(int1) + str1)

Output:

10test在 Python 中的反斜杠上拆分字符串

s = r'canada\japan\australia'l = s.split('\\')print(l)

Output:

['canada', 'japan', 'australia']在Python中随机大写字符串中的字母

from random import choicex = "canada japan australia"print(''.join(choice((str.upper, str.lower))(c) for c in x))

Output:

CANaDA JaPan auStRALIa在单词处拆分字符串并且或不保留分隔符

import restring = "Canada AND Japan NOT Audi OR BMW"l = re.split(r'(AND|OR|NOT)', string)print(l)

Output:

['Canada ', 'AND', ' Japan ', 'NOT', ' Audi ', 'OR', ' BMW']在 Python 中填充 n 个字符

def header(txt: str, width=30, filler='*', align='c'): assert align in 'lcr' return {'l': txt.ljust, 'c': txt.center, 'r': txt.rjust}[align](width, filler) print(header("Canada"))print(header("Canada", align='l'))print(header("Canada", align='r'))

Output:

************Canada************Canada************************************************Canada检查变量是否等于一个字符串或另一个字符串

x = 'canada'if x in ['canada', 'japan', 'germany', 'australia']: print("Yes")

Output:

truePython字符串格式化固定宽度

num1 = 0.04154721841num2 = 10.04154721841num3 = 1002.04154721841print "{0:<12.11g}".format(num1)[:12]print "{0:<12.11g}".format(num2)[:12]print "{0:<12.11g}".format(num3)[:12]

Output:

100.0415490.0415987412.8878877在Python中查找字符串中字符的所有位置

test = 'canada#japan#uae'c = '#'print([pos for pos, char in enumerate(test) if char == c])

Output:

[6, 12]在Python中从左右修剪指定数量的空格

def trim(text, num_of_leading, num_of_trailing): text = list(text) for i in range(num_of_leading): if text[i] == " ": text[i] = "" else: break for i in range(1, num_of_trailing+1): if text[-i] == " ": text[-i] = "" else: break return ''.join(text)txt1 = " Candada "print(trim(txt1, 1, 1))print(trim(txt1, 2, 3))print(trim(txt1, 6, 8))

Output:

Candada Candada Candada在Python中按字符串中字符的位置拆分字符串

str = 'canadajapan'splitat = 6l, r = str[:splitat], str[splitat:]print(l)print(r)

Output:

canadajapan将Python字符串中的第一个和最后一个字母大写

string = "canada"result = string[0:1].upper() + string[1:-1].lower() + string[-1:].upper()print(result)

Output:

CanadA检查字符串是否以Python中的给定字符串或字符结尾

txt = "Canada is a great country"x = txt.endswith("country")print(x)

Output:

True如何在 Python 中比较两个字符串

str1 = "Canada"str2 = "Canada"print(str1 is str2) # Trueprint(str1 == str2) # True string1 = ''.join(['Ca', 'na', 'da'])string2 = ''.join(['Can', 'ada'])print(string1 is string2) # Falseprint(string1 == string2) # True

Output:

TrueTrueFalseTrue在Python中将整数格式化为带有前导零的字符串

x = 4x = str(x).zfill(5)print(x)

Output:

s = "The quick brown fox jumps over the lazy dog"for r in (("brown", "red"), ("lazy", "quick")): s = s.replace(*r)print(s)

Output:

The quick red fox jumps over the quick dogPython字符串替换字符

s = "The quick brown fox jumps over the lazy dog"for r in (("brown", "red"), ("lazy", "quick")): s = s.replace(*r)print(s)

Output:

The quick red fox jumps over the quick dog在Python中查找字符串中所有出现的单词的所有索引

import resentence = 'this is a sentence this this'word = 'this'for match in re.finditer(word, sentence): print(match.start(), match.end())

Output:

import stringx = "they're bill's friends from the UK"x = string.capwords(x)print(x)x = x.title()print(x)

Output:

They're Bill's Friends From The UkThey'Re Bill'S Friends From The Uk仅在 Python 中的双引号后拆分字符串

s = '"Canada", "Japan", "Germany", "Russia"'l = ['"{}"'.format(s) for s in s.split('"') if s not in ('', ', ')]for item in l: print(item)

Output:

"Canada""Japan""Germany""Russia"在 Python 中以字节为单位获取字符串的大小

string1 = "Canada"print(len(string1.encode('utf-16')))

Output:

myString = 'AAABBB'for idx, char in enumerate(myString, ): if idx + 1 == len(myString): break if char == myString[idx + 1]: print(idx, char, myString[idx + 1])

Output:

0 A A1 A A3 B B4 B B在 Python 中的括号和字符串之间添加空格

import retest = "example(test)"test2 = "example(test)example"test3 = "(test)example"test4 = "example (test) example"for i in [test, test2, test3, test4]: print(re.sub(r"[^\S]?(\(.*?\))[^\S]?", r" \1 ", i).strip())

Output:

example (test)example (test) example(test) exampleexample (test) example在 Python 中删除开头和结尾空格

s = ' canada 'print(s.strip())

Output:

canada在 Python 中拆分字符串以获得第一个值

s = 'canada-japan-australia'l = s.split('-')[0]print(l)string = 'canada-japan-australia'print(string[:string.index('-')])

Output:

canadacanada在 Python 中检查字符串是大写、小写还是混合大小写

words = ['The', 'quick', 'BROWN', 'Fox', 'jumped', 'OVER', 'the', 'Lazy', 'DOG']print([word for word in words if word.islower()])print([word for word in words if word.isupper()])print([word for word in words if not word.islower() and not word.isupper()])

Output:

['quick', 'jumped', 'the']['BROWN', 'OVER', 'DOG']['The', 'Fox', 'Lazy']Python计数字符串出现在给定字符串中

txt = "I love Canada, Canada is one of the most impressive countries in the world. Canada is a great country." x = txt.count("Canada") print(x)

Output:

hour = 4minute = 3print("{:0>2}:{:0>2}".format(hour, minute))print("{:0>3}:{:0>5}".format(hour, minute))print("{:0<3}:{:0<5}".format(hour, minute))print("{:$<3}:{:#<5}".format(hour, minute))

Output:

04:03004:00003400:300004$$:3####在 Python 中检查两个字符串是否包含相同的字母和数字

from string import ascii_letters, digitsdef compare_alphanumeric(first, second): for character in first: if character in ascii_letters + digits and character not in second: return False return Truestr1 = 'ABCD'str2 = 'ACDB'print(compare_alphanumeric(str1, str2))str1 = 'A45BCD'str2 = 'ACD59894B'print(compare_alphanumeric(str1, str2))str1 = 'A45BCD'str2 = 'XYZ9887'print(compare_alphanumeric(str1, str2))

Output:

TrueTrueFalse在Python中的字符串中的字符之间添加空格的有效方法

s = "CANADA"print(" ".join(s))print("-".join(s))print(s.replace("", " ")[1: -1])

Output:

C A N A D AC-A-N-A-D-AC A N A D A在Python中查找字符串中最后一次出现的子字符串的索引

s = 'What is Canada famous for?'print(s.find('f'))print(s.index('f'))print(s.rindex('f'))print(s.rfind('f'))

Output:

x = 'canada'x = x.capitalize() print(x)

Output:

Canada拆分非字母数字并在 Python 中保留分隔符

import res = "65&Can-Jap#Ind^UK"l = re.split('([^a-zA-Z0-9])', s)print(l)

Output:

['65', '&', 'Can', '-', 'Jap', '#', 'Ind', '^', 'UK']计算Python中字符串中大写和小写字符的数量

string = "asdfHRbySFss"uppers = [l for l in string if l.isupper()]print(len(uppers))lowers = [l for l in string if l.islower()]print(len(lowers))

Output:

from enum import Enum, autoclass Signal(Enum): red = auto() green = auto() orange = auto() def equals(self, string): return self.name == stringbrain_detected_colour = "red"print(Signal.red.equals(brain_detected_colour))brain_detected_colour = "pink"print(Signal.red.equals(brain_detected_colour))

Output:

TrueFalsePython中的段落格式

import textwraphamlet = '''\Lorum ipsum is the traditional Latin placeholder text, used when a designer needs a chunk of text for dummying up a layout.Journo Ipsum is like that, only using some of the most common catchphrases, buzzwords, and bon mots of the future-of-news crowd.Hit reload for a new batch. For entertainment purposes only.'''wrapper = textwrap.TextWrapper(initial_indent='\t' * 1, subsequent_indent='\t' * 2, width=40)for para in hamlet.splitlines(): print(wrapper.fill(para))

Output:

Lorum ipsum is the traditional Latinplaceholder text, used when a designerneeds a chunk of text for dummying upa layout.Journo Ipsum is like that, only usingsome of the most common catchphrases,buzzwords, and bon mots of the future-of-news crowd.Hit reload for a new batch. Forentertainment purposes only.从 Python 中的某个索引替换字符

def nth_replace(str,search,repl,index): split = str.split(search,index+1) if len(split)<=index+1: return str return search.join(split[:-1])+repl+split[-1]str1 = "caars caars caars"str2 = nth_replace(str1, 'aa', 'a', 1)print(str2)

Output:

caars cars caars如何连接 str 和 int 对象

i = 123a = "foobar"s = a + str(i)print(s)

Output:

foobar123仅在 Python 中将字符串拆分为两部分

s = 'canada japan australia'l = s.split(' ', 1)print(l)

Output:

['canada', 'japan australia']将大写字符串转换为句子大小写

text = ['CANADA', 'JAPAN']text = [txt.capitalize() for txt in text]print(text)

Output:

['Canada', 'Japan']在标点符号上拆分字符串

string = 'a,b,c d!e.f\ncanada\tjapan&germany'identifiers = '!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~\n\t 'listitems = "".join((' ' if c in identifiers else c for c in string)).split()for item in listitems: print(item)

Output:

abcdefcanadajapangermany在 Python 中比较字符串

str1 = "Canada"str2 = "Canada"print(str1 is str2) # Trueprint(str1 == str2) # True string1 = ''.join(['Ca', 'na', 'da'])string2 = ''.join(['Can', 'ada'])print(string1 is string2) # Falseprint(string1 == string2) # True

Output:

TrueTrueFalseTrue用零填充数字字符串

num = 123print('{:<08d}'.format(num))print('{:>08d}'.format(num))string = '123'print(string.ljust(8, '0'))print(string.rjust(8, '0'))print(string[::-1].zfill(8)[::-1])

Output:

def dif(a, b): return [i for i in range(len(a)) if a[i] != b[i]]print(dif('stackoverflow', 'stacklavaflow'))

Output:

[5, 6, 7, 8]Python填充字符串到固定长度

number = 4print(f'{number:05d}') # (since Python 3.6), orprint('{:05d}'.format(number)) # orprint('{0:05d}'.format(number))print('{n:05d}'.format(n=number)) # or (explicit `n` keyword arg. selection)print(format(number, '05d'))

Output:

import retext = 'This is sample text to test if this pythonic '\ 'program can serve as an indexing platform for '\ 'finding words in a paragraph. It can give '\ 'values as to where the word is located with the '\ 'different examples as stated'find_the_word = re.finditer('as', text)for match in find_the_word: print('start {}, end {}, search string \'{}\''. format(match.start(), match.end(), match.group()))

Output:

start 63, end 65, search string 'as'start 140, end 142, search string 'as'start 200, end 202, search string 'as'删除字符串中的开头零和结尾零

list_num = ['000231512-n', '1209123100000-n00000', 'alphanumeric0000', '000alphanumeric'] print([item.strip('0') for item in list_num]) # Remove leading + trailing '0'print([item.lstrip('0') for item in list_num]) # Remove leading '0'print([item.rstrip('0') for item in list_num]) # Remove trailing '0'

Output:

['231512-n', '1209123100000-n', 'alphanumeric', 'alphanumeric']['231512-n', '1209123100000-n00000', 'alphanumeric0000', 'alphanumeric']['000231512-n', '1209123100000-n', 'alphanumeric', '000alphanumeric']Python在换行符上拆分

s = 'line 1\nline 2\nline without newline'l = s.splitlines(True)print(l)

Output:

['line 1\n', 'line 2\n', 'line without newline']将字符串中的每个第二个字母大写

s = 'canada's = "".join([x.upper() if i % 2 != 0 else x for i, x in enumerate(s)])print(s)

Output:

cAnAdA在 Python 中查找一个月的最后一个营业日或工作日

import calendardef last_business_day_in_month(year: int, month: int) -> int: return max(calendar.monthcalendar(year, month)[-1:][0][:5])print(last_business_day_in_month(2021, 1))print(last_business_day_in_month(2021, 2))print(last_business_day_in_month(2021, 3))print(last_business_day_in_month(2021, 4))print(last_business_day_in_month(2021, 5))

Output:

def compare_strings(a, b): result = True if len(a) != len(b): print('string lengths do not match!') for i, (x, y) in enumerate(zip(a, b)): if x != y: print(f'char miss-match {x, y} in element {i}') result = False if result: print('strings match!') return resultprint(compare_strings("canada", "japan"))

Output:

string lengths do not match!char miss-match ('c', 'j') in element 0char miss-match ('n', 'p') in element 2char miss-match ('d', 'n') in element 4False在 Python 中多次显示字符串

print('canada' * 3)print(*3 * ('canada',), sep='-')

Output:

canadacanadacanadacanada-canada-canadaPython从头开始替换字符串

def nth_replace(s, old, new, occurrence): li = s.rsplit(old, occurrence) return new.join(li)str1 = "caars caars caars caars caars"str2 = nth_replace(str1, 'aa', 'a', 1)print(str2)str2 = nth_replace(str1, 'aa', 'a', 2)print(str2)str2 = nth_replace(str1, 'aa', 'a', 3)print(str2)

Output:

caars caars caars caars carscaars caars caars cars carscaars caars cars cars cars在 Python 中连接字符串和变量值

year = '2020'print('test' + str(year))print('test' + year.__str__())

Output:

test2020test2020在每个下划线处拆分字符串并在第 N 个位置后停止

s = 'canada_japan_australia_us_uk'l = s.split('_', 0)print(l)l = s.split('_', 1)print(l)l = s.split('_', 2)print(l)

Output:

['canada_japan_australia_us_uk']['canada', 'japan_australia_us_uk']['canada', 'japan', 'australia_us_uk']Python中列表中第一个单词的首字母大写

text = ['johnny rotten', 'eddie vedder', 'kurt kobain', 'chris cornell', 'micheal phillip jagger']text = [txt.capitalize() for txt in text]print(text)

Output:

['Johnny rotten', 'Eddie vedder', 'Kurt kobain', 'Chris cornell', 'Micheal phillip jagger']如何在 Python 字符串中找到第一次出现的子字符串

test = 'Position of a character'print(test.find('of'))print(test.find('a'))

Output:

data = [1148, 39, 365, 6, 56524]for element in data: print("{:>5}".format(element))

Output:

def after(s1, s2): index = s1.find(s2) if index != -1 and index + len(s2) < len(s1): return s1[index + len(s2):] else: return Nones1 = "canada"s2 = "can"print(after(s1, s2))

Output:

ada如何用Python中的一个字符替换字符串中的所有字符

test = 'canada'print('$' * len(test))

Output:

$$$$$$在字符串中查找子字符串并在 Python 中返回子字符串的索引

def find_str(s, char): index = 0 if char in s: c = char[0] for ch in s: if ch == c: if s[index:index + len(char)] == char: return index index += 1 return -1print(find_str("India Canada Japan", "Canada"))print(find_str("India Canada Japan", "cana"))print(find_str("India Canada Japan", "Uae"))

Output:

6-1-1从 Python 中的字符串中修剪特定的开头和结尾字符

number = '+91 874854778'print(number.strip('+'))print(number.lstrip('+91'))

Output:

string = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"x = 3res = [string[y - x:y] for y in range(x, len(string) + x, x)]print(res)

Output:

['ABC', 'DEF', 'GHI', 'JKL', 'MNO', 'PQR', 'STU', 'VWX', 'YZ']如何在 Python 中将字符串的第三个字母大写

s = "xxxyyyzzz"# convert to lista = list(s)# change every third letter in place with a list comprehensiona[2::3] = [x.upper() for x in a[2::3]]# back to a strings = ''.join(a)print(s)

Output:

xxXyyYzzZ将制表符大小设置为指定的空格数

txt = "Canada\tis\ta\tgreat\tcountry"print(txt)print(txt.expandtabs())print(txt.expandtabs(2))print(txt.expandtabs(4))print(txt.expandtabs(10))

Output:

CanadaisagreatcountryCanada is a great countryCanada is a great countryCanada is a great countryCanada is a great country将两个字符串与某些字符进行比较

str1 = "Can"str2 = "Canada"print(str1 in str2)print(str1.startswith(str2))print(str2.startswith(str1))print(str1.endswith(str2))str3 = "CAN"print(str3 in str2)

Output:

TrueFalseTrueFalseFalse字符串格式化填充负数

n = [-2, -8, 1, -10, 40]num = ["{1:0{0}d}".format(2 if x >= 0 else 3, x) for x in n]print(num)

Output:

n = [-2, -8, 1, -10, 40]num = ["{1:0{0}d}".format(2 if x >= 0 else 3, x) for x in n]print(num)单独替换字符串中的第一个字符

str1 = "caars caars caars"str2 = str1.replace('aa', 'a', 1)print(str2)

Output:

cars caars caars连接固定字符串和变量

variable = 'Hello'print('This is the Test File ' + variable)variable = '10'print('This is the Test File ' + str(variable))

Output:

This is the Test File HelloThis is the Test File 10将字符串拆分为多个字符串

s = 'str1, str2, str3, str4'l = s.split(', ') print(l)

Output:

['str1', 'str2', 'str3', 'str4']在 Python 中将字符串大写

x = "canada japan australia"x = x[:1].upper() + x[1:]print(x)x= x.capitalize()print(x)x= x.title()print(x)

Output:

Canada japan australiaCanada japan australiaCanada Japan Australia将字节字符串拆分为单独的字节

data = b'\x00\x00\x00\x00\x00\x00'info = [data[i:i + 2] for i in range(0, len(data), 2)]print(info)

Output:

[b'\x00\x00', b'\x00\x00', b'\x00\x00']用空格填写 Python 字符串

string = 'Hi'.ljust(10)print(string)string = 'Hi'.rjust(10)print(string)string = '{0: ^20}'.format('Hi')print(string)string = '{message: >16}'.format(message='Hi')print(string)string = '{message: <16}'.format(message='Hi')print(string)string = '{message: <{width}}'.format(message='Hi', width=20)print(string)

Output:

Hi Hi Hi HiHi Hi比较两个字符串并检查它们共有多少个字符

from collections import Counterdef shared_chars(s1, s2): return sum((Counter(s1) & Counter(s2)).values())print(shared_chars('car', 'carts'))

Output:

import res = "ABC24.00XYZ58.28PQR"s = re.sub("[A-Za-z]+", lambda group: " " + group[0] + " ", s)print(s.strip())

Output:

ABC 24.00 XYZ 58.28 PQR如何在 Python 中去除空格

s = ' canada 'print(s.rstrip()) # For whitespace on the right side use rstrip.print(s.lstrip()) # For whitespace on the left side lstrip.print(s.strip()) # For whitespace from both side. s = ' \t canada 'print(s.strip('\t')) # This will strip any space, \t, \n, or \r characters from the left-hand side, right-hand side, or both sides of the string.

Output:

canadacanada canada canada字符串中最后一次出现的分隔符处拆分字符串

s = 'canada-japan-australia-uae-india'l = s.rsplit('-', 1)[1]print(l)

Output:

india在Python中将字符串的最后一个字母大写

string = "canada"result = string[:-1] + string[-1].upper()print(result)result = string[::-1].title()[::-1]print(result)

Output:

canadAcanadA使用指定字符居中对齐字符串

txt = "canada"x = txt.center(20)print(x)

Output:

canada格式字符串中动态计算的零填充

x = 4w = 5print('{number:0{width}d}'.format(width=w, number=x))

Output:

a = "This is the island of istanbul"print (a.replace("is" , "was", 1))print (a.replace("is" , "was", 2))print (a.replace("is" , "was"))

Output:

Thwas is the island of istanbulThwas was the island of istanbulThwas was the wasland of wastanbul在 Python 中获取字符的位置

test = 'Position of a character'print(test.find('of'))print(test.find('a'))

Output:

s = "The quick brown fox jumps over the lazy dog"for r in (("brown", "red"), ("lazy", "quick")): s = s.replace(*r)print(s)

Output:

The quick red fox jumps over the quick dog在索引后找到第一次出现的字符

string = 'This + is + a + string'x = string.find('+', 4)print(x)x = string.find('+', 10)print(x)

Output:

x = 'canada'x = x.upper()print(x)

Output:

CANADA在 Python 中拆分具有多个分隔符的字符串

import rel = re.split(r'[$-]+', 'canada$-india$-japan$-uae')print(l)

Output:

['canada', 'india', 'japan', 'uae']在 Python 中获取字符串的大小

string1 = "Canada"print(len(string1))string2 = " Canada"print(len(string2))string3 = "Canada "print(len(string3))

Output:

x = 'canada'y = ''.join(['ca', 'na', 'da'])print(x == y)print(x is y) x = [1, 2, 3]y = [1, 2, 3]print(x == y)print(x is y) z = yprint(z is y)

Output:

TrueFalseTrueFalseTrue每当数字与非数字相邻时，Python 正则表达式都会添加空格

import retext = ['123', 'abc', '4x5x6', '7.2volt', '60BTU', '20v', '4*5', '24in', 'google.com-1.2', '1.2.3']pattern = r'(-?[0-9]+\.?[0-9]*)'for data in text: print(repr(data), repr( ' '.join(segment for segment in re.split(pattern, data) if segment)))

Output:

'123' '123''abc' 'abc''4x5x6' '4 x 5 x 6''7.2volt' '7.2 volt''60BTU' '60 BTU''20v' '20 v''4*5' '4 * 5''24in' '24 in''google.com-1.2' 'google.com -1.2''1.2.3' '1.2 . 3'在 Python 中仅按第一个空格拆分字符串

s = 'canada japan australia'l = s.split(' ', 1)print(l)

Output:

['canada', 'japan australia']在Python中将字符串中的一些小写字母更改为大写

indices = set([0, 7, 14, 18])s = "i love canada and japan"print("".join(c.upper() if i in indices else c for i, c in enumerate(s)))

Output:

I love Canada And Japan将字符串拆分为具有多个单词边界分隔符的单词

import rethestring = "a,b,c d!e.f\ncanada\tjapan&germany"listitems = re.findall('\w+', thestring)for item in listitems: print(item)

Output:

abcdefcanadajapangermany检查一个字符串在 Python 中是否具有相同的字符

str1 = 'caars'str2 = 'rats'str3 = 'racs'print(set(str1)==set(str2))print(set(str1)==set(str3))

Output:

FalseTrue在多个分隔符或指定字符上拆分字符串

import re string_test = "Ethnic (279), Responses (3), 2016 Census - 25% Sample"print(re.findall(r"[\w']+", string_test)) def split_by_char(s, seps): res = [s] for sep in seps: s, res = res, [] for seq in s: res += seq.split(sep) return res print(split_by_char(string_test, [' ', '(', ')', ',']))

Output:

['Ethnic', '279', 'Responses', '3', '2016', 'Census', '25', 'Sample']['Ethnic', '', '279', '', '', 'Responses', '', '3', '', '', '2016', 'Census', '-', '25%', 'Sample']将一个字符串附加到另一个字符串

# Example 1str1 = "Can"str2 = "ada"str3 = str1 + str2print(str3) # Example 2str4 = 'Ca'str4 += 'na'str4 += 'da'print(str4) # Example 3join_str = "".join((str1, str2))print(join_str) # Example 4str_add = str1.__add__(str2)print(str_add)

Output:

CanadaCanadaCanadaCanada在 Python 中遍历字符串

# Example 1test_str = "Canada"for i, c in enumerate(test_str): print(i, c) print("------------------------") # Example 2indx = 0while indx < len(test_str): print(indx, test_str[indx]) indx += 1 print("------------------------")# Example 3for char in test_str: print(char)

Output:

0 C1 a2 n.......da从 Python 中的字符串中去除标点符号

import stringimport re # Example 1s = "Ethnic (279), Responses (3), 2016 Census - 25% Sample"out = re.sub(r'[^\w\s]', '', s)print(out) # Example 2s = "Ethnic (279), Responses (3), 2016 Census - 25% Sample"for p in string.punctuation: s = s.replace(p, "")print(s) # Example 3s = "Ethnic (279), Responses (3), 2016 Census - 25% Sample"out = re.sub('[%s]' % re.escape(string.punctuation), '', s)print(out)

Output:

Ethnic 279 Responses 3 2016 Census 25 SampleEthnic 279 Responses 3 2016 Census 25 SampleEthnic 279 Responses 3 2016 Census 25 Sample将列表转换为字符串

list_exp = ['Ca', 'na', 'da']print(type(list_exp)) # Example 1str_exp1 = ''.join(list_exp)print(type(str_exp1))print(str_exp1) # Example 2str_exp2 = ''.join(str(e) for e in list_exp)print(type(str_exp2))print(str_exp2) # Example 3str_exp3 = ''.join(map(str, list_exp))print(type(str_exp2))print(str_exp2)

Output:

class 'list'class 'str'Canadaclass 'str'Canadaclass 'str'Canada将 JSON 转换为字符串

import json # list with dict a simple Json formatjson_exp = \ [{"id": "12", "name": "Mark"}, {"id": "13", "name": "Rock", "date": None}]print(type(json_exp)) str_conv = json.dumps(json_exp) # stringprint(type(str_conv))print(str_conv)

Output:

class 'list'class 'str'[{"id": "12", "name": "Mark"}, {"id": "13", "name": "Rock", "date": null}]对字符串列表进行排序

# Example 1str_list = ["Japan", "Canada", "Australia"]print(str_list)str_list.sort()print(str_list) # Example 2str_list = ["Japan", "Canada", "Australia"]for x in sorted(str_list): print(x) # Example 3str_var = "Canada"strlist = sorted(str_var)print(strlist)

Output:

['Japan', 'Canada', 'Australia']['Australia', 'Canada', 'Japan']AustraliaCanadaJapan['C', 'a', 'a', 'a', 'd', 'n']在 Python 中检查字符串是否以 XXXX 开头

import re exp_str = "Python Programming" # Example 1if re.match(r'^Python', exp_str): print(True)else: print(False) # Example 2result = exp_str.startswith("Python")print(result)

Output:

TrueTrue在 Python 中将两个字符串网格或交错在一起的不同方法

str1 = "AAAA"str2 = "BBBBBBBBB" # Example 1mesh = "".join(i + j for i, j in zip(str1, str2))print("Example 1:", mesh) # Example 2min_len = min(len(str1), len(str2))mesh = [''] * min_len * 2mesh[::2] = str1[:min_len]mesh[1::2] = str2[:min_len]print("Example 2:", ''.join(mesh)) # Example 3mesh = ''.join(''.join(item) for item in zip(str1, str2))print("Example 3:", mesh) # Example 4min_len = min(len(str1), len(str2))mesh = [''] * min_len * 2mesh[::2] = str1[:min_len]mesh[1::2] = str2[:min_len]mesh += str1[min_len:] + str2[min_len:]print("Example 4:", ''.join(mesh))

Output:

Example 1: ABABABABExample 2: ABABABABExample 3: ABABABABExample 4: ABABABABBBBBB