Added Bollinger Bands Tutorial File

Author: PyDataBlog

Tutorials/Bollinger Bands Tutorial.py

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+# import needed libraries
+import pandas as pd
+import matplotlib.pyplot as plt
+from pandas_datareader import data as web
+
+# Make function for calls to Yahoo Finance
+def get_adj_close(ticker, start, end):
+    '''
+    A function that takes ticker symbols, starting period, ending period
+    as arguments and returns with a Pandas DataFrame of the Adjusted Close Prices
+    for the tickers from Yahoo Finance
+    '''
+    start = start
+    end = end
+    info = web.DataReader(ticker, data_source='yahoo', start=start, end=end)['Adj Close']
+    return pd.DataFrame(info)
+
+# Get Adjusted Closing Prices for Facebook, Tesla and Amazon between 2016-2017
+fb = get_adj_close('fb', '1/2/2016', '31/12/2017')
+tesla = get_adj_close('tsla', '1/2/2016', '31/12/2017')
+amazon = get_adj_close('amzn', '1/2/2016', '31/12/2017')
+
+# Calculate 30 Day Moving Average, Std Deviation, Upper Band and Lower Band
+for item in (fb, tesla, amazon):
+    item['30 Day MA'] = item['Adj Close'].rolling(window=20).mean()
+    item['30 Day STD'] = item['Adj Close'].rolling(window=20).std()
+    item['Upper Band'] = item['30 Day MA'] + (item['30 Day STD'] * 2)
+    item['Lower Band'] = item['30 Day MA'] - (item['30 Day STD'] * 2)
+
+# Simple 30 Day Bollinger Band for Facebook (2016-2017)
+fb[['Adj Close', '30 Day MA', 'Upper Band', 'Lower Band']].plot(figsize=(12,6))
+plt.title('30 Day Bollinger Band for Facebook')
+plt.ylabel('Price (USD)')
+plt.show()
+
+# set style, empty figure and axes
+plt.style.use('fivethirtyeight')
+fig = plt.figure(figsize=(12,6))
+ax = fig.add_subplot(111)
+
+# Get index values for the X axis for facebook DataFrame
+x_axis = fb.index.get_level_values(0)
+
+# Plot shaded 21 Day Bollinger Band for Facebook
+ax.fill_between(x_axis, fb['Upper Band'], fb['Lower Band'], color='grey')
+
+# Plot Adjust Closing Price and Moving Averages
+ax.plot(x_axis, fb['Adj Close'], color='blue', lw=2)
+ax.plot(x_axis, fb['30 Day MA'], color='black', lw=2)
+
+# Set Title & Show the Image
+ax.set_title('30 Day Bollinger Band For Facebook')
+ax.set_xlabel('Date (Year/Month)')
+ax.set_ylabel('Price(USD)')
+ax.legend()
+plt.show()