How to create new column in Dataframe using condition on existing columns?

Question

Trying to create the new column in my dataframe based on the below condition:

dataFrame01['final'] = dataFrame01.apply(lambda x: x['Name'] if x['Eval'] == 'NAN' else x['Eval'], axis=1)

but every time only ELSE block is getting executed I mean values from else condition as getting populated but not from IF conditions. Please help and let me know what mistake I am doing here.

Difficult to answer unless you share the actual data in the pandas dataframe. — Biranchi
– Biranchi, Commented Apr 29, 2020 at 12:46
For the next time, please spend a minute to see how to properly format your code (done it for you this time). Also, this is a standard pandas question, and it has nothing to do with machine-learning - kindly do not spam irrelevant tags (removed). — desertnaut
– desertnaut, Commented Apr 29, 2020 at 12:50
is your data string NAN or np.nan? Also check for leading/trailing white spaces. — Quang Hoang
– Quang Hoang, Commented Apr 29, 2020 at 12:58

sng · Accepted Answer · 2020-04-29 13:19:17Z

1

Hard to say without seeing the data. It appears as though the below expression is not getting evaluated.

x['Eval'] == 'NAN'

As a hunch, check that you are specifying your NaN correctly. In Pandas, missing values are typically specified as np.nan. One way to evaluate missing values in Pandas is with pd.isnull(). Thus, the code would look something like this:

dataFrame01['final'] = dataFrame01.apply(lambda x: x['Name'] if pd.isnull(x['Eval']) else x['Eval'], axis=1)

answered Apr 29, 2020 at 13:19

sng

1077 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to create new column in Dataframe using condition on existing columns?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related