Replace A Value In A Dataframe With A Value From Another Dataframe

I have a replacing problem in python. I'm trying to replace all the integer value in the column ORIGIN_AIRPORT from df_2 with the IATA column from df_1. The key-columns are ORIGIN_

Solution 1:

I am going to write the simplest solution for this :

Step 1: Convert both columns from df_1 into a dictionary by using the following code:

d = dict(zip(df_1.ID,df_1.IATA))

Step 2: Now we just need to map this dictionary and df_2:

df_2.ORIGIN_AIRPORT= df_1.ID.map(d)

Solution 2:

You can do a left join of df_1 and df_2.

Given the moderate size of df1, you can just create a mapping rule:

mapping = {}
for row in df_1.iterrows():
    mapping[row[0]] = row[1]

And create a new column:

df2['AIRPORT_PROCESSED'] = df2['ORIGIN_AIRPORT'].apply(lambda x: mapping.get(x, x))

The last function will replace ORIGIN_AIRPORT value for the value from mapping if x is in mapping.