Python itertools库中product函数使用实例探究

`itertools.product(*iterables, repeat=1)`

import itertools
# 示例 1：两个集合的笛卡尔积
iterable1 = [1, 2]
iterable2 = ['a', 'b']
result = list(itertools.product(iterable1, iterable2))
print(result)
# Output: [(1, 'a'), (1, 'b'), (2, 'a'), (2, 'b')]
# 示例 2：三个集合的笛卡尔积
iterable3 = ['x', 'y']
result = list(itertools.product(iterable1, iterable2, iterable3))
print(result)
# Output: [(1, 'a', 'x'), (1, 'a', 'y'), (1, 'b', 'x'), (1, 'b', 'y'),
#          (2, 'a', 'x'), (2, 'a', 'y'), (2, 'b', 'x'), (2, 'b', 'y')]

import itertools
# 示例：两个集合的笛卡尔积，每个元素重复两次
iterable1 = [1, 2]
iterable2 = ['a', 'b']
result = list(itertools.product(iterable1, iterable2, repeat=2))
print(result)
# Output: [(1, 'a', 1, 'a'), (1, 'a', 1, 'b'), (1, 'a', 2, 'a'), (1, 'a', 2, 'b'),
#          (1, 'b', 1, 'a'), (1, 'b', 1, 'b'), (1, 'b', 2, 'a'), (1, 'b', 2, 'b'),
#          (2, 'a', 1, 'a'), (2, 'a', 1, 'b'), (2, 'a', 2, 'a'), (2, 'a', 2, 'b'),
#          (2, 'b', 1, 'a'), (2, 'b', 1, 'b'), (2, 'b', 2, 'a'), (2, 'b', 2, 'b')]

import itertools
# 示例：懒惰计算的笛卡尔积
iterable1 = [1, 2, 3]
iterable2 = ['a', 'b', 'c']
product_iter = itertools.product(iterable1, iterable2)
# 只有在迭代时才会生成组合
for item in product_iter:
    print(item)
    # Output: (1, 'a'), (1, 'b'), (1, 'c'), (2, 'a'), (2, 'b'), (2, 'c'), (3, 'a'), (3, 'b'), (3, 'c')