使用 Python 创建列表列表

Question

Having a data frame as below:need to convert to list of list as below:

product1	product2	time
Apple	Apple	0
Apple	Mango	20
Apple	Orange	24
Mango	Apple	30
Mango	Mango	0
Mango	Orange	24
orange	Apple	12
orange	orange	0
orange	mango	24

Need to create a matrix whose logic is like this:

The output needs to be a list of list of format as below:

[[0,24,20],[12,0,24],[30,24,0]]

I tried the below code:

df.groupby(['product1','product2'])['time'].apply(list)

Answer 1

From the looks of this, this is known as a pivot table. You can create it by using pandas.pivot_table method.

To create the above matrix, you need to write this code.

pt = data.pivot_table(index="product1", columns="product2", values="time")

To get this in list of list form. Store this in a variable and use this.

pt.values.tolist()