How to find minimum value of each row from a list of specific columns

Question

Here are 4 rows and 4 columns.

a b c d
1 8 2 6
3 6 7 9
1 5 9 4
1 0 6 8

I want column 'e' as shown below but below code gives me NaN as output in entire 'e' column.

df["e"]= df.loc[:, ["b", "c", "d"].min()

Desired Output

a b c d e
1 8 2 6 1
3 6 7 9 3
1 5 9 4 1
1 0 6 8 0

Answer 1

Use

df['e'] = df.min(axis=1)

That'll get your the minimum across all columns, row wise.

Answer 2

df["e"]= df.loc[:, ["b", "c", "d"]].min(axis = 1) instead as it has to give the minimum by itering in columns.