NumPy > Groupby column using count

Name
Code
Output
dataframe = pandas.DataFrame(numpy.random.randint(0,5,size=(5, 3)), columns=['C1','C2','C3'])
print ("dataframe")
print (dataframe)
aggregate = dataframe.groupby('C1').count()
print ("aggregated data")
print (aggregate)
dataframe
   C1  C2  C3
0   2   4   4
1   4   1   1
2   2   0   1
3   3   3   2
4   0   2   4
aggregated data
    C2  C3
C1        
0    1   1
2    2   2
3    1   1
4    1   1