map output the key value if key not in dict

January 21, 2022

import pandas as pd

d = {'user': ['bob','alice','bob', 'kk'],
     'item': ['apple','coconut','pear', 'ajay']}
df = pd.DataFrame(data = d)

d = {'apple':1.0,'coconut':0.0}
df['item'] = df['item'].map(d)

Output: df
Out[22]: 
    user  item
0    bob   1.0
1  alice   0.0
2    bob   NaN
3    kk    NaN

Expected output:
Output: df
Out[22]: 
    user  item
0    bob   1.0
1  alice   0.0
2    bob   pear
3    kk    ajay

Above is my piece with the output and expected output. When I am using map. I am getting NaN for key not in map.
My expected output post mapping is below:

Output: df
Out[22]: 
    user  item
0    bob   1.0
1  alice   0.0
2    bob   pear
3    kk    ajay

is it possible to excluded the entry which can’t be mapped?

>Solution :

Use Series.fillna by original column:

d = {'apple':1.0,'coconut':0.0}
df['item'] = df['item'].map(d).fillna(df['item'])

print (df)
    user  item
0    bob   1.0
1  alice   0.0
2    bob  pear
3     kk  ajay

Or use Series.replace:

d = {'apple':1.0,'coconut':0.0}
df['item'] = df['item'].replace(d)

print (df)
    user  item
0    bob   1.0
1  alice   0.0
2    bob  pear
3     kk  ajay