%matplotlib inline

import matplotlib.pyplot as plt
import pandas as pd

url = "http://mlr.cs.umass.edu/ml/machine-learning-databases/iris/iris.data"

# Define our headers since the url doesn't contain explicit headers
# I found these headers from looking at the documentation at
# http://mlr.cs.umass.edu/ml/machine-learning-databases/iris/iris.names
headers = ['Sepal Length', 'Sepal Width', 'Petal Length', 'Petal Width', 'Class'
	]
iris = pd.read_csv(url, header=None, names=headers)

iris[:3]

# I use two brackets around 'Sepal Length' to force pandas to make this
# a data frame rather than just a series, which is like a numpy array.
# The brackets here aren't necessary, but makes printing sepal_lengths
# prettier and makes it easier for us to combine sepal_lengths with other
# data.
sepal_lengths = iris[['Sepal Length']]

# Make the plot pretty!
pd.set_option('display.mpl_style', 'default') 

sepal_lengths.hist()