Get the element of a list in Dataframe based on column values in Pandas-CodePudding

I want to select one specific element of a column of lists based on another columns cell value in a Pandas Dataframe.

    list_column    value
0   [a, b, c]      0
1   [a, b, c]      2
2   [a, b, c]      1

so the desired output will be:

    list_column     value   selected
0   [a, b, c]       0       a
1   [a, b, c]       2       c
2   [a, b, c]       1       b

I tried using the df["selected"] = df['list'].str[df["value"]] but was not managing to apply this correctly.

CodePudding user response：

I've checked the previous solution doesn't work I've tested this one it works
for index, row in df.iterrows():
value = row['values']
df.loc[index,"selected"] = df.loc[index,'list_column'][value]

CodePudding user response：

For a vectorial approch use numpy slicing:

import numpy as np

df['selected'] = np.vstack(df['list_column'])[np.arange(len(df)), df['value']]

Output:

  list_column  value selected
0   [a, b, c]      0        a
1   [a, b, c]      2        c
2   [a, b, c]      1        b