精心整理了100+Python字符串常用操作，收藏备用！（下）

水深无声 2023-10-10 14:18 28阅读 0赞

**简介：** 精心整理了100+Python字符串常用操作，收藏备用！（下）

### 在 Python3 中用前导零填充字符串 ###

--------------------

hour = 4
    minute = 3
    print("{: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:

04:03
    004:00003
    400:30000
    4$$: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, digits
    def compare_alphanumeric(first, second):
        for character in first:
            if character in ascii_letters + digits and character not in second:
                return False
        return True
    str1 = '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:

True
    True
    False

### 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 A
    C-A-N-A-D-A
    C 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:

15
    15
    22
    22

### 在 Python 中将字符串大写 ###

--------------------

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 re
    s = "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:

4
    8

### 在 Python 中将字符串与枚举进行比较 ###

--------------------

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

Output:

True
    False

### Python中的段落格式 ###

--------------------

import textwrap
    hamlet = '''\
    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 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.

### 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 = 123
    a = "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:

a
    b
    c
    d
    e
    f
    canada
    japan
    germany

### 在 Python 中比较字符串 ###

--------------------

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

Output:

True
    True
    False
    True

### 用零填充数字字符串 ###

--------------------

num = 123
    print('{:<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:

12300000
    00000123
    12300000
    00000123
    12300000

### 找到两个字符串之间的差异位置 ###

--------------------

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

Output:

00004
    00004
    00004
    00004
    00004
    00004

### Python中的字符串查找示例 ###

--------------------

import re
    text = '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 calendar
    def 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:

29
    26
    31
    30
    31

### 比较两个字符串中的单个字符 ###

--------------------

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 result
    print(compare_strings("canada", "japan"))

Output:

string lengths do not match!
    char miss-match ('c', 'j') in element 0
    char miss-match ('n', 'p') in element 2
    char miss-match ('d', 'n') in element 4
    False

### 在 Python 中多次显示字符串 ###

--------------------

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

Output:

canadacanadacanada
    canada-canada-canada

### Python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 cars
    caars caars caars cars cars
    caars 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:

test2020
    test2020

### 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:

9
    12

### 不同长度的Python填充字符串 ###

--------------------

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

Output:

1148
       39
      365
        6
    56524

### Python比较两个字符串保留一端的差异 ###

--------------------

def after(s1, s2):
        index = s1.find(s2)
        if index != -1 and index + len(s2) < len(s1):
            return s1[index + len(s2):]
        else:
            return None
    s1 = "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 -1
    print(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:

91 874854778
     874854778

### 在 Python 中按长度将字符串拆分为字符串 ###

--------------------

string = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    x = 3
    res = [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 list
    a = list(s)
    # change every third letter in place with a list comprehension
    a[2::3] = [x.upper() for x in a[2::3]]
    # back to a string
    s = ''.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:

Canada  is  a great country
    Canada  is      a       great   country
    Canada  is  a great country
    Canada  is  a   great   country
    Canada    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:

True
    False
    True
    False
    False

### 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 Hello
    This 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 australia
    Canada japan australia
    Canada 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         
                  Hi
    Hi              
    Hi

### 比较两个字符串并检查它们共有多少个字符 ###

--------------------

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

Output:

### 在 Python 中的数字和字符串之间添加空格 ###

--------------------

import re
    s = "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:

canada
    canada  
    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:

canadA
    canadA

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

Output:

00004

### 在 Python 中使用 string.replace() ###

--------------------

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 istanbul
    Thwas was the island of istanbul
    Thwas 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:

9
    12

### Python字符串替换多次出现 ###

--------------------

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:

5
    10

### 在 Python 中将字符串更改为大写 ###

--------------------

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 re
    l = 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:

6
    8
    8

### Python中的字符串比较 is vs == ###

--------------------

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 = y
    print(z is y)

Output:

True
    False
    True
    False
    True

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

--------------------

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

Output:

a
    b
    c
    d
    e
    f
    canada
    japan
    germany

### 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:

False
    True

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

Output:

Canada
    Canada
    Canada
    Canada

### 在 Python 中遍历字符串 ###

--------------------

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

Output:

0 C
    1 a
    2 n
    .......
    d
    a

### 从 Python 中的字符串中去除标点符号 ###

--------------------

import string
    import re
     
    # Example 1
    s = "Ethnic (279), Responses (3), 2016 Census - 25% Sample"
    out = re.sub(r'[^\w\s]', '', s)
    print(out)
     
    # Example 2
    s = "Ethnic (279), Responses (3), 2016 Census - 25% Sample"
    for p in string.punctuation:
            s = s.replace(p, "")
    print(s)
     
    # Example 3
    s = "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 Sample
    Ethnic 279 Responses 3 2016 Census  25 Sample
    Ethnic 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 1
    str_exp1 = ''.join(list_exp)
    print(type(str_exp1))
    print(str_exp1)
     
    # Example 2
    str_exp2 = ''.join(str(e) for e in list_exp)
    print(type(str_exp2))
    print(str_exp2)
     
    # Example 3
    str_exp3 = ''.join(map(str, list_exp))
    print(type(str_exp2))
    print(str_exp2)

Output:

class 'list'
    class 'str'
    Canada
    class 'str'
    Canada
    class 'str'
    Canada

### 将 JSON 转换为字符串 ###

--------------------

import json
     
     
    # list with dict a simple Json format
    json_exp = \
        [{"id": "12", "name": "Mark"}, {"id": "13", "name": "Rock", "date": None}]
    print(type(json_exp))
     
    str_conv = json.dumps(json_exp)  # string
    print(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 1
    str_list = ["Japan", "Canada", "Australia"]
    print(str_list)
    str_list.sort()
    print(str_list)
     
    # Example 2
    str_list = ["Japan", "Canada", "Australia"]
    for x in sorted(str_list):
        print(x)
     
    # Example 3
    str_var = "Canada"
    strlist = sorted(str_var)
    print(strlist)

Output:

['Japan', 'Canada', 'Australia']
    ['Australia', 'Canada', 'Japan']
    Australia
    Canada
    Japan
    ['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 1
    if re.match(r'^Python', exp_str):
        print(True)
    else:
        print(False)
     
    # Example 2
    result = exp_str.startswith("Python")
    print(result)

Output:

True
    True

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