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Given the following text description, write Python code to implement the functionality described below step by step
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Description:
 Comparing Different Stream Environments
This Jupyter Notebook compares four streams in different environments in the U.S. 
Using hydrofunctions, we are able to plot the flow duration graphs for all four streams and compare them.
Step1:  Choose four streams from different environments from HydroCloud. Import data for three years. 
In this example, all four streams are in places with low development
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Python Code:
import hydrofunctions as hf
%matplotlib inline
Explanation: Comparing Different Stream Environments
This Jupyter Notebook compares four streams in different environments in the U.S. 
Using hydrofunctions, we are able to plot the flow duration graphs for all four streams and compare them.
End of explanation
streams = ['09073400','11480390','01074520','09498502']
sites = hf.NWIS(streams, 'dv', start_date='2001-01-01', end_date='2003-12-31')
sites
#Create a dataframe of the four sites
Q = sites.df('discharge')
#Show the first few lines of the dataframe
Q.head()
# rename the columns based on the names of the sites from HydroCloud
Q.columns=['White Mountains National Park', 'White River National Forest', 'Tonto National Forest', 'Mendicino National Park']
# show the first few rows of the data to confirm the changes
Q.head()
#use the built-in functions from hydrofunctions to create a flow duration graph for the dataframe.
hf.flow_duration(Q)
#Pull the stats for each of the four sites.
Q.describe()
Explanation: Choose four streams from different environments from HydroCloud. Import data for three years. 
In this example, all four streams are in places with low development:
Colorado Western Slopes: ROARING FORK RIVER NEAR ASPEN, CO.
California Mendicino National Park: MAD R AB RUTH RES NR FOREST GLEN CA
White Mountains, NH: EAST BRANCH PEMIGEWASSET RIVER AT LINCOLN, NH
PINTO CREEK NEAR MIAMI, AZ
End of explanation
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