python代码例子

当提供一个 Python 代码例子时，我需要知道您对什么样的功能或主题感兴趣。

Hello World:

python
print("Hello, World!")

变量和运算:

python
# 变量
x = 5
y = 10

# 运算
z = x + y
print("Sum:", z)

条件语句:

python
age = 20

if age >= 18:
    print("You are an adult.")
else:
    print("You are a minor.")

循环:

python
# for 循环
for i in range(5):
    print(i)

# while 循环
count = 0
while count < 5:
    print(count)
    count += 1

函数:

python
def add_numbers(a, b):
    return a + b

result = add_numbers(3, 7)
print("Sum:", result)

列表和循环:

python
# 列表
fruits = ["apple", "banana", "orange"]

# for 循环遍历列表
for fruit in fruits:
    print(fruit)

异常处理:

python
try:
    # 产生一个除零错误
    result = 10 / 0
except ZeroDivisionError:
    print("Error: Division by zero")

文件操作:

python
# 写入文件
with open('example.txt', 'w') as file:
    file.write('Hello, File!\n')

# 读取文件
with open('example.txt', 'r') as file:
    content = file.read()
    print("File Content:", content)

类和对象:

python
# 定义一个类
class Dog:
    def __init__(self, name):
        self.name = name

    def bark(self):
        print(f"{self.name} says Woof!")

# 创建对象
my_dog = Dog("Buddy")

# 调用方法
my_dog.bark()

模块和导入:

python
# 创建一个模块，例如 calculator.py
# calculator.py 文件内容：
# def add(a, b):
#     return a + b

# 在另一个文件中导入模块
from calculator import add

result = add(3, 5)
print("Sum:", result)

正则表达式:

python
import re

text = "Hello, my email is user@example.com"

# 使用正则表达式查找电子邮件地址
match = re.search(r'[\w.-]+@[\w.-]+', text)
if match:
    email = match.group()
    print("Email:", email)