Is it possible from dataframe transform to Matrix?

Question

I am newbie in python, I have a huge dataframe:

Person  OD
A       BS1
A       BS2
B       BS4
B       BS8
C       BS5
C       BS1
D       BS9
D             


        

Answer 1

Following is a solution.

places = df["OD"].unique()
places.sort()
od_df = pd.DataFrame(df["OD"].values.reshape((-1, 2)), columns=["O", "D"])
od_matrix = od_df.groupby(["O", "D"]).size().unstack().reindex(index=places, columns=places)
od_matrix.fillna(0, downcast="infer", inplace=True)

You can also use pd.pivot_table and replace the fourth line with

od_matrix = pd.pivot_table(od_df, index="O", columns="D", aggfunc="size").reindex(index=places, columns=places)