How to retrieve rows of a Pandas GroupBy object in for loop

Question

I have a group by object.I want to retrieve rows of a particular column of the group by object in for loop & do some processing. For example,I'm giving here a sample code for group by object

df = pd.DataFrame({'A' : ['foo', 'bar', 'foo', 'bar',
                             'foo', 'bar', 'foo', 'foo'],
                       'B' : ['one', 'one', 'two', 'three',
                              'two', 'two', 'one', 'three'],
                       'C' : np.random.randn(8),
                       'D' : np.random.randn(8)})
grouped = df.groupby(['A', 'B'])

After group by, I got following object

In a for loop I would like to do some check if it's one,two or three & then do some processing.Can you please suggest me the steps?

Answer 1

you can loop in the group_by object like this :

for index, row in grouped:
    print (index) #index is a tuple 
    print(row) #row is a new dataframe 

To check what you are looking for you can do this(ie: check if a value is in a certain column of a dataframe do this):

for index, row in grouped:
    if -0.83026 in row.get("C").values: # "C" or any column name you want
        print("hello")

for your data the output will be something like this :

('bar', 'one')
     A    B        C         D
1  bar  one -0.83026  0.983017
('bar', 'three')
     A      B         C         D
3  bar  three -0.381041  1.538971
('bar', 'two')
     A    B         C         D
5  bar  two -0.963402  0.201348
('foo', 'one')
     A    B         C         D
0  foo  one  0.691410  0.328420
6  foo  one -1.521541 -0.188345
('foo', 'three')
     A      B         C         D
7  foo  three -0.817304 -0.359331
('foo', 'two')
     A    B         C         D
2  foo  two -0.528639 -0.999301
4  foo  two -1.018919  0.661665