python - 相当于分组数据的合并，两个列表生成dataframe，但长度不同

Question

举个例子

ntest=['a','b']
ltest=[[1,2],[4,5,6]]

最后我想得到下面这种结果：
a 1
a 2
b 4
b 5
b 6
这种该怎么做呢？

Answer 1

# coding: utf-8

import pandas as pd

ntest = ['a','b']
ltest = [[1,2], [4,5,6]]

data = [(k, v) for k, l in zip(ntest, ltest) for v in l]

print pd.DataFrame(data)

Answer 2

If the structure of the second array is determined, you can first split the second array into a one-dimensional array, and then traverse the two arrays to generate a dataframe.