Python中的叉积/笛卡尔积

您可以使用itertools.product。假设L为您的资料栏df['dates']-

from itertools import product

l = [201801,201802]
out = pd.DataFrame(list(product(l,l)))
print(out)

        0       1
0  201801  201801
1  201802  201801
2  201801  201802
3  201802  201802

或者，您可以简单地使用列表推导来迭代l 2次。

out = pd.DataFrame([(j,i) for i in l for j in l])
print(out)

        0       1
0  201801  201801
1  201802  201801
2  201801  201802
3  201802  201802