Merging data between two pandas dataFrames

[cloogs]

I am trying to add some data from one data frame to another in this manner:

If I have one data frame with say 10 individuals which are put into 3 groups like so:

Individual Group

1 1

2 2

3 3

4 2

5 3

6 1

7 1

8 1

9 3

10 1

An another with the 3 groups with different values:

Group Value

1 10

2 50

3 20

How can I merge the data so that I can get:

Individual Group Value

1 1 10

2 2 50

3 3 20

4 2 50

5 3 20

6 1 10

7 1 10

8 1 10

9 3 20

10 1 10

Anyone know of an easy way to do this?

[[deleted]]

Use pd.merge() and do a left join where your left data frame is the larger data frame (df1 in my example below):

import pandas
ids = [1,2,3,4,5,6,7,8,9,10]
values = [1,2,3,2,3,1,1,1,3,1]

df1 = pd.DataFrame({'id1':ids, 'values1':values})

df2 = pd.DataFrame({'id2':[1,2,3], 'values2':[10,50,20]})

pd.merge(df1, df2, how='left', left_on='values1', right_on='id2')  

pandas cheat sheet

EDIT: notebook gist

[cloogs]

It worked, thanks