CODEWITHSUNDEEP
pythonpandasif-statementmerge
Maneet Giri
Maneet Giri

Reputation: 185

How to merge in python based on condition?

I would like to know if there is a possible way to merge two dataframes by giving an 'if' statement. For example

df

number account_name  classification
     1        name         named
     2        place        partner
     3        animal       class
     4        thing        territory
     5        dog          home

df1

account_name   Number   country
name            1         xx
place           2         xy
animal          7         yz
dog             8         zx

I am looking for a code like below

pd.merge(df,df1, on= 'account_name') if df[number] == df1[number]

the result sould be like

number  account_name  classification  number Country
     1        name         named          1      xx
     2        place        partner        2      xy

I tried the lambda function as well, code was

x['nn'] = x.apply(lambda y: pd.merge(df, df1, on = 'account_name')  if df[number] == df1[number] else 1, axis=1)

Upvotes: 3

Views: 2958

Answers (1)

jezrael
jezrael

Reputation: 863291

It seems you need add column to parameter on:

df = pd.merge(df,df1, on= ['account_name', 'number']) 
print (df)
   number account_name classification country
0       1         name          named      xx
1       2        place        partner      xy

But if column names are different use parameters left_on and right_on in merge:

df = pd.merge(df, 
              df1, 
              left_on= ['account_name', 'number'], 
              right_on= ['account_name', 'Number']) 
print (df)
   number account_name classification  Number country
0       1         name          named       1      xx
1       2        place        partner       2      xy

Upvotes: 4

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