How to perform a group by function in Python?

To perform a groupby function, we need to create a dataframe.Let us create a dataframe.

import pandas as pd

# Create dataframe

data = {'Company':['GOOG','GOOG','MSFT','MSFT','FB','FB'],

       'Person':['Sam','Charlie','Amy','Vanessa','Carl','Sarah'],

       'Sales':[200,120,340,124,243,350]}

df = pd.DataFrame(data)

df

The dataframe looks like below

Now we can use the .groupby() method to group rows together based off of a column name. For instance let's group based off of Company. This will create a DataFrameGroupBy object

df.groupby('Company')

We can save this object as a new variable:

by_comp = df.groupby("Company")

And then call aggregate methods off the object:

by_comp.mean()