Python嵌套循环的实现示例

for 外层变量 in 外层可迭代对象:
    for 内层变量 in 内层可迭代对象:
        # 循环体代码

for i in range(1, 10):
    for j in range(1, i+1):
        print(f"{j}x{i}={i*j}", end="\t")
    print()

matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
for row in matrix:
    for item in row:
        print(item, end=" ")
    print()

for i in range(3):
    j = 0
    while j < 3:
        print(f"i={i}, j={j}")
        j += 1

i = 1
while i <= 3:
    j = 1
    while j <= i:
        print(j, end=" ")
        j += 1
    print()
    i += 1

for i in range(3):
    for j in range(3):
        if j == 1:
            break
        print(f"i={i}, j={j}")

found = False
for i in range(3):
    for j in range(3):
        if i == 1 and j == 1:
            found = True
            break
    if found:
        break

def find_target():
    for i in range(3):
        for j in range(3):
            if i == 1 and j == 1:
                print("找到目标！")
                return

find_target()

image = [[(255, 0, 0), (0, 255, 0)], [(0, 0, 255), (255, 255, 0)]]
for row in image:
    for pixel in row:
        print(pixel)

users = ["Alice", "Bob"]
products = ["iPhone", "MacBook"]

for user in users:
    for product in products:
        print(f"{user} 推荐了 {product}")

n = 5
for i in range(n):
    for j in range(i+1):
        print("*", end="")
    print()

set1 = {1, 2, 3}
set2 = {2, 3, 4}

common = []
for a in set1:
    for b in set2:
        if a == b:
            common.append(a)

print("交集：", common)