'''
Pivoting duplicate values

So far, you've used the .pivot_table() method when there are multiple index values 
you want to hold constant during a pivot. In the video, Dan showed you how you can 
also use pivot tables to deal with duplicate values by providing an aggregation 
function through the aggfunc parameter. Here, you're going to combine both these 
uses of pivot tables.

Let's say your data collection method accidentally duplicated your dataset. Such a 
dataset, in which each row is duplicated, has been pre-loaded as airquality_dup. In 
addition, the airquality_melt DataFrame from the previous exercise has been 
pre-loaded. Explore their shapes in the IPython Shell by accessing their .shape 
attributes to confirm the duplicate rows present in airquality_dup.

You'll see that by using .pivot_table() and the aggfunc parameter, you can not only 
reshape your data, but also remove duplicates. Finally, you can then flatten the 
columns of the pivoted DataFrame using .reset_index().

NumPy and pandas have been imported as np and pd respectively.

INSTRUCTIONS
100 XP
Pivot airquality_dup by using .pivot_table() with the rows indexed by 'Month' and 'Day', the columns indexed by 'measurement', and the values populated with 'reading'. Use np.mean for the aggregation function.
Flatten airquality_pivot by resetting its index.
Print the head of airquality_pivot and then the original airquality DataFrame to compare their structure.
'''
