replace column values with values in another list when values appear in a specific list

Question

Hi I have a list and a pandas dataframe

[ apple, tomato, mango ]

values 

tomato
pineapple
apple
banana
mango

I would like to replace the column values that appear in the list with the values in the new list as follow

[ fruit1, fruit2, fruit3 ]

My expected output is a pandas dataframe that looks like this

values 

fruit2
pineapple
fruit1
banana
fruit3

How can I accomplish this efficiently?

Asked By: nerd

||

Source

Answer 1

Create a dict and use the map function of a dataframe:

l1 = ["apple", "tomato", "mango"]
l2 = ["fruit1", "fruit2", "fruit3"]

df['values'].map(dict(zip(l1, l2))).fillna(df['values'])

fillna is needed because map by default will convert values that doesn’t exists in dict to NaN.

Answered By: kosciej16

Answer 2

Create a dictionary with the zip() function and then replace the values:

current = ['apple', 'tomato', 'mango']
to_replace = ['fruit1', 'fruit2', 'fruit3']

replace_dict = dict(zip(current, to_replace))

df.replace(replace_dict, inplace=True)

print(df)

      values
0     fruit2
1  pineapple
2     fruit1
3     banana
4     fruit3

The replace function replaces dataframe values. Hope it helps!

Answered By: Pythoneer

replace column values with values in another list when values appear in a specific list

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