Python中可以通過使用嵌套循環(huán)或使用itertools.product()
函數(shù)來實現(xiàn)笛卡爾積算法。
方法一:使用嵌套循環(huán)
def cartesian_product(lists):
result = [[]]
for lst in lists:
result = [x+[y] for x in result for y in lst]
return result
lists = [[1, 2, 3], ['a', 'b', 'c'], ['x', 'y']]
result = cartesian_product(lists)
print(result)
輸出結果:
[[1, 'a', 'x'], [1, 'a', 'y'], [1, 'b', 'x'], [1, 'b', 'y'], [1, 'c', 'x'], [1, 'c', 'y'], [2, 'a', 'x'], [2, 'a', 'y'], [2, 'b', 'x'], [2, 'b', 'y'], [2, 'c', 'x'], [2, 'c', 'y'], [3, 'a', 'x'], [3, 'a', 'y'], [3, 'b', 'x'], [3, 'b', 'y'], [3, 'c', 'x'], [3, 'c', 'y']]
方法二:使用itertools.product()
函數(shù)
import itertools
lists = [[1, 2, 3], ['a', 'b', 'c'], ['x', 'y']]
result = list(itertools.product(*lists))
print(result)
輸出結果與方法一相同:
[(1, 'a', 'x'), (1, 'a', 'y'), (1, 'b', 'x'), (1, 'b', 'y'), (1, 'c', 'x'), (1, 'c', 'y'), (2, 'a', 'x'), (2, 'a', 'y'), (2, 'b', 'x'), (2, 'b', 'y'), (2, 'c', 'x'), (2, 'c', 'y'), (3, 'a', 'x'), (3, 'a', 'y'), (3, 'b', 'x'), (3, 'b', 'y'), (3, 'c', 'x'), (3, 'c', 'y')]