具有可变范围的任意嵌套for循环(python)

# 定义两个列表
list1 = [1, 2, 3]
list2 = ['a', 'b']

# 使用嵌套for循环生成所有可能的组合
combinations = []
for item1 in list1:
    for item2 in list2:
        combinations.append((item1, item2))

# 输出结果
print(combinations)

import time

start_time = time.time()
for i in range(1000):
    for j in range(1000):
        result = i * j  # 假设这是一个复杂的计算
end_time = time.time()
print(f"原始运行时间: {end_time - start_time}秒")

import time
from functools import lru_cache

@lru_cache(maxsize=None)
def compute(i, j):
    return i * j  # 假设这是一个复杂的计算

start_time = time.time()
for i in range(1000):
    for j in range(1000):
        _ = compute(i, j)  # 使用缓存的结果
end_time = time.time()
print(f"优化后运行时间: {end_time - start_time}秒")