Unable to use matplotlib

I have downloaded matplotlib through my python terminal, in addition, I have anaconda installed on my computer. I am trying to execute this code, although the second and fourth line are greyed out, and thus cannot be run. I have tried deleting these lines and the green play button is still grey. 

import datetime as dt
import matplotlib.pyplot as plt
from matplotlib import style
import pandas as pd
import pandas_datareader.data as web

style.use('ggplot')

start = dt.datetime(2015, 1, 1)
end = dt.datetime.now()
df = web.DataReader("TSLA", 'morningstar', start, end)
df.reset_index(inplace=True)
df.set_index("Date", inplace=True)
df = df.drop("Symbol", axis=1)

print(df.head())