Adding column value for a list of indexes

Question

I have a list of indexes and trying to populate a column 'Type' for these rows only.

What I tried to do:

index_list={1,5,9,10,13} 
df.loc[index_list,'Type']=="gain+loss"

Output:
1      False
5      False
9      False
10     False
13     False

But the output just gives the list with all False instead of populating these rows. Thanks for any advice.

Answer 1

You need to put a single equal instead of double equal. In python, and in most progamming languages, == is the comparison operator. In your case you need the assignment operator =. So the following code will do what you want :

index_list={1,5,9,10,13} 
df.loc[index_list,'Type']="gain+loss"