30 段即取即用的极简 Python 代码

在 Python 编程的世界里，简洁而高效的代码往往能事半功倍。以下为您精心整理了 30 段极简的 Python 代码，让您在编程过程中即取即用。

1. 打印“Hello, World!”

print("Hello, World!")

2. 计算两个数的和

num1 = 5
num2 = 10
sum = num1 + num2
print(sum)

3. 判断一个数是奇数还是偶数

num = 7
if num % 2 == 0:
    print("偶数")
else:
    print("奇数")

4. 遍历列表

list1 = [1, 2, 3, 4, 5]
for item in list1:
    print(item)

5. 计算列表元素之和

list2 = [10, 20, 30, 40, 50]
total = sum(list2)
print(total)

6. 找出列表中的最大值

list3 = [8, 18, 28, 38, 48]
max_value = max(list3)
print(max_value)

7. 交换两个变量的值

a = 5
b = 10
a, b = b, a
print("a =", a, "b =", b)

8. 生成一个指定范围内的随机数

import random
random_number = random.randint(1, 100)
print(random_number)

9. 计算阶乘

def factorial(n):
    if n == 0 or n == 1:
        return 1
    else:
        return n * factorial(n - 1)
print(factorial(5))

10. 反转字符串

string = "Python"
reversed_string = string[::-1]
print(reversed_string)

11. 判断字符串是否为回文

def is_palindrome(string):
    return string == string[::-1]
print(is_palindrome("racecar"))

12. 计算字符串中某个字符出现的次数

string1 = "hello world"
count = string1.count('l')
print(count)

13. 去除字符串两端的空格

string2 = "   Python   "
trimmed_string = string2.strip()
print(trimmed_string)

14. 将字符串转换为大写

string3 = "python is great"
upper_case_string = string3.upper()
print(upper_case_string)

15. 计算两个日期之间的天数差

from datetime import date
date1 = date(2023, 1, 1)
date2 = date(2023, 10, 1)
delta = date2 - date1
print(delta.days)

16. 读取文件内容

with open("file.txt", "r") as file:
    content = file.read()
    print(content)

17. 写入内容到文件

with open("new_file.txt", "w") as file:
    file.write("This is new content.")

18. 复制文件

import shutil
shutil.copy("source.txt", "destination.txt")

19. 创建一个目录

import os
os.mkdir("new_directory")

20. 列出指定目录下的文件和子目录

import os
directory = "/path/to/directory"
for item in os.listdir(directory):
    print(item)

21. 捕获异常

try:
    result = 10 / 0
except ZeroDivisionError:
    print("不能除以零")

22. 定义一个类

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def introduce(self):
        print(f"我叫{self.name}，今年{self.age}岁。")

23. 继承一个类

class Student(Person):
    def __init__(self, name, age, grade):
        super().__init__(name, age)
        self.grade = grade

    def study(self):
        print(f"{self.name}在{self.grade}年级学习。")

24. 使用正则表达式匹配字符串

import re
string4 = "Hello 123 World"
match = re.search(r'\d+', string4)
if match:
    print(match.group())

25. 对列表进行排序

list4 = [5, 2, 8, 1, 9]
sorted_list = sorted(list4)
print(sorted_list)

26. 对字典按值排序

dict1 = {'a': 5, 'b': 2, 'c': 8}
sorted_dict = sorted(dict1.items(), key=lambda x: x[1])
print(sorted_dict)

27. 计算列表的平均值

list5 = [10, 20, 30, 40, 50]
average = sum(list5) / len(list5)
print(average)

28. 实现快速排序算法

def quick_sort(arr):
    if len(arr) <= 1:
        return arr
    pivot = arr[len(arr) // 2]
    left = [x for x in arr if x < pivot]
    middle = [x for x in arr if x == pivot]
    right = [x for x in arr if x > pivot]
    return quick_sort(left) + middle + quick_sort(right)

print(quick_sort([9, 8, 7, 6, 5]))

29. 实现冒泡排序算法

def bubble_sort(arr):
    n = len(arr)

    for i in range(n):
        for j in range(0, n - i - 1):
            if arr[j] > arr[j + 1] :
                arr[j], arr[j + 1] = arr[j + 1], arr[j]

    return arr

print(bubble_sort([9, 8, 7, 6, 5]))

30. 实现插入排序算法

def insertion_sort(arr):
    for i in range(1, len(arr)):
        key = arr[i]
        j = i - 1
        while j >= 0 and key < arr[j] :
            arr[j + 1] = arr[j]
            j -= 1
        arr[j + 1] = key
    return arr

print(insertion_sort([9, 8, 7, 6, 5]))

这些极简的 Python 代码片段涵盖了各种常见的编程任务，希望能为您的编程之旅提供便利和灵感。不断练习和运用，您将更加熟练地掌握 Python 编程。