pandas_datareader is a good package for downloading stocks data. It uses pandas, which can be used to perform analysis. In this example, the stock price for Netflix is downloaded and plotted. Also, a rolling 60-days average is added to the plot.

import datetime
import matplotlib.pyplot as plt
import pandas as pd
import pandas_datareader
# Download the Stock
s = pandas_datareader.get_data_yahoo("NFLX", start=datetime.datetime(2018,1,1))
# Plot it
plt.figure(figsize=(10, 5))
plt.plot(s["Adj Close"], label="NFLX")
plt.plot(s["Adj Close"].rolling(60).mean(), label="60 Days Rolling Mean")
plt.xticks(rotation=90)
plt.grid()
plt.legend()
plt.show()

Note: remember to pip install pandas matplotlib pandas_datareader