python关键字

# Python关键字示例代码

# 1. if-else语句
x = 10
if x > 5:
    print("x is greater than 5")
else:
    print("x is not greater than 5")

# 2. for循环
for i in range(5):
    print(f"Current value of i is {i}")

# 3. while循环
count = 0
while count < 3:
    print(f"Count is {count}")
    count += 1

# 4. def定义函数
def greet(name):
    return f"Hello, {name}!"

print(greet("Alice"))

# 5. class定义类
class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def introduce(self):
        return f"My name is {self.name} and I am {self.age} years old."

person = Person("Bob", 30)
print(person.introduce())

# 6. try-except异常处理
try:
    result = 10 / 0
except ZeroDivisionError:
    print("You cannot divide by zero!")

# 7. with语句（上下文管理器）
with open('example.txt', 'w') as file:
    file.write('Hello, world!')

# 8. lambda表达式
add = lambda x, y: x + y
print(add(5, 3))

# 9. import导入模块
import math
print(math.sqrt(16))

# 10. global和nonlocal关键字
global_var = "I am global"

def outer_function():
    nonlocal_var = "I am nonlocal"

    def inner_function():
        global global_var
        nonlocal nonlocal_var
        global_var = "Changed global"
        nonlocal_var = "Changed nonlocal"
        print(global_var)
        print(nonlocal_var)

    inner_function()

outer_function()
print(global_var)

# 解释说明：
# 以上代码展示了Python中一些常见的关键字用法，包括条件语句、循环、函数定义、类定义、异常处理、上下文管理器、lambda表达式、模块导入以及global和nonlocal关键字的使用。