import pandas as pd
import numpy as np

!cat PreisMoatStanley_ScientificReports_3_1684_2013.dat | head -n 2

df = pd.read_csv('PreisMoatStanley_ScientificReports_3_1684_2013.dat', delimiter=' ')
columns = ['Google Start Date', 'Google End Date', 'debt', 'DJIA Date', 'DJIA Closing Price']
df = df[columns]
df.head()

debt_from_study = df[['debt']]
debt_from_study.index = df['Google End Date']
debt_from_study.index = debt_from_study.index.to_datetime()
debt_from_study.head()

debt_us_as_of_20130528 = pd.read_csv('debt_US_google_trend.csv', index_col='date')
debt_us_as_of_20130528.index = debt_us_as_of_20130528.index.to_datetime()
debt_us_as_of_20130528.head()

debt_compare = pd.merge(debt_from_study, debt_us_as_of_20130528, left_index=True, right_index=True, how='outer')
debt_compare.head()

import matplotlib.pyplot as plt

fig, ax = plt.subplots()
ax2 = ax.twinx()

debt_compare.debt_x.plot(ax=ax, style='b-')
debt_compare.debt_y.plot(ax=ax2, style='r-', secondary_y=True)