Let it be the following Python Pandas DataFrame.

Using the next code:

dictionary = {'GER': 'Germany', 'FRA': 'France'}
df['region'] = df['region'].map(dictionary)

I get the following result:

My idea is that the values that do not appear in the dictionary, keep their previous values.

How could I do this? Thank you in advance.

CodePudding user response：

I think what you want is that :

df.replace({"region": dictionary})

CodePudding user response：

Use fillna (or combine_first):

df['region'] = df['region'].map(dictionary).fillna(df['region'])

or take advantage of the get method to set the value as default:

df['region'] = df['region'].map(lambda x: dictionary.get(x, x))

output:

   ID   region
0  12   France
1  99  Germany
2  13      ESP
3  69       UK
4  17  Germany
5   2  Germany