#!/usr/bin/env python
# coding: utf-8

# ![Pandas Tutorial | Hedaro >](https://www.dropbox.com/s/220ncn0o5danuey/pandas-ipython-tutorials-hedaro.jpg?dl=1)
# # Lesson 6

# > Lets take a look at the ***groupby*** function.

# In[1]:


# Import libraries
import pandas as pd
import sys


# In[2]:


print('Python version ' + sys.version)
print('Pandas version ' + pd.__version__)


# In[3]:


# Our small data set
d = {'one':[1,1,1,1,1],
     'two':[2,2,2,2,2],
     'letter':['a','a','b','b','c']}

# Create dataframe
df = pd.DataFrame(d)
df


# In[4]:


# Create group object
one = df.groupby('letter')

# Apply sum function
one.sum()


# In[5]:


letterone = df.groupby(['letter','one']).sum()
letterone


# In[6]:


letterone.index


# You may want to ***not*** have the columns you are grouping by become your index, this can be easily achieved as shown below.

# In[7]:


letterone = df.groupby(['letter','one'], as_index=False).sum()
letterone


# In[8]:


letterone.index


# <p class="text-muted">This tutorial was created by <a href="http://www.hedaro.com" target="_blank"><strong>HEDARO</strong></a></p>