Python for 和 while 循环：掌握循环控制的基本操作

2024-12-24
北京
本文字数：1668 字
阅读完需：约 5 分钟

本文详细介绍了 Python 中的 for 和 while 循环的使用方法，帮助你轻松掌握循环控制的基本操作。通过 for 循环，你可以在有限范围内迭代执行代码块，而 while 循环则适用于条件控制的场景，甚至可以实现无限循环。此外，文章还讲解了 continue 和 break 关键字的作用，分别用于跳过当前循环或终止循环。通过丰富的代码示例，本文展示了如何在不同情况下使用这些循环结构，使你的代码更加灵活和高效。文章最后附有完整的代码示例，便于读者实际操作和理解。

一 for 循环

    # for 循环 python    for i in range(5):        print("新文件-" + str(i))    print()    for i in range(2, 5):        print("新文件-" + str(i))    print()    for i in range(3, 10, 2):        print("新文件-" + str(i))

复制代码

二 while 循环

    guess_num = 10    while guess_num != 20:        guess_num += 1        print(guess_num)

复制代码

三两个循还的特点

四 continue 和 break

    # continue 和 break    count = 0    guess_num = 30    while guess_num != 20 and count <= 10:        guess_num -= 1        count += 1        print(guess_num)    print()
    count = 0    guess_num = 10    while guess_num != 20:        guess_num += 1        count += 1        if count > 10:            break        print(guess_num)    print()    for i in range(10):        if i == 5:            break        print(i)    print()    for i in range(10):        if i % 2 == 0:            continue  # 跳过偶数        print(i)

复制代码

注解

五完整文件示例

# This is a sample Python script.
# Press ⌃R to execute it or replace it with your code.# Press Double ⇧ to search everywhere for classes, files, tool windows, actions, and settings.

def print_hi(name):    # Use a breakpoint in the code line below to debug your script.    print(f'Hi, {name}')  # Press ⌘F8 to toggle the breakpoint.    # for 循环    for i in range(5):        print("新文件-" + str(i))    print()    for i in range(2, 5):        print("新文件-" + str(i))    print()    for i in range(3, 10, 2):        print("新文件-" + str(i))    print()    # While 循环    # for  天然适合在有限的循环中    # while  可以被用在无限循环中    guess_num = 10    while guess_num != 20:        guess_num += 1        print(guess_num)    print()    # continue 和 break    count = 0    guess_num = 30    while guess_num != 20 and count <= 10:        guess_num -= 1        count += 1        print(guess_num)    print()
    count = 0    guess_num = 10    while guess_num != 20:        guess_num += 1        count += 1        if count > 10:            break        print(guess_num)    print()    for i in range(10):        if i == 5:            break        print(i)    print()    for i in range(10):        if i % 2 == 0:            continue  # 跳过偶数        print(i)    # break  中止循环    # continue 跳出当前循环，进行下一个循环

# Press the green button in the gutter to run the script.if __name__ == '__main__':    print_hi('for 和 while 循环')
# See PyCharm help at https://www.jetbrains.com/help/pycharm/

复制代码

复制粘贴并覆盖到你的 main.py 中运行，运行结果如下。

Hi, for 和 while 循环新文件-0新文件-1新文件-2新文件-3新文件-4
新文件-2新文件-3新文件-4
新文件-3新文件-5新文件-7新文件-9
11121314151617181920
29282726252423222120
11121314151617181920
01234
13579