Pandas - AttributeError: 'DataFrame' object has no attribute 'map'

Question

I am trying to create a new column in an dataframe, by creating a dictionary based on an existing column and calling the 'map' function on the column. It seemed to be working for quite some time. However, the notebook started throwing

AttributeError: 'DataFrame' object has no attribute 'map'

I haven't changed the kernel or the python version. Here's the code i am using.

dict= {1:A,
       2:B,
       3:C,
       4:D,
       5:E}

# Creating an interval-type 
data['new'] = data['old'].map(dict)

how to fix this?

Answer 1

map is a method that you can call on a pandas.Series object. This method doesn't exist on pandas.DataFrame objects.

df['new'] = df['old'].map(d)

In your code ^^^ df['old'] is returning a pandas.Dataframe object for some reason.

• As @jezrael points out this could be due to having more than one old column in the dataframe.

• Or perhaps your code isn't quite the same as the example you have given.

• Either way the error is there because you are calling map() on a pandas.Dataframe object