Plot Train-Test Split Data

The following code shows how to plot the data for a train-test split of a time series data set

# plot train-test split of time series data
import pandas as pd
import matplotlib.pyplot as plt

series = pd.read_csv('sunspots.csv', header=0, index_col=0, 
                  parse_dates=True).squeeze('columns')
X = series.values
train_size = int(len(X) * 0.66)
train, test = X[0:train_size], X[train_size:len(X)]

plt.figure(figsize=(16,8))
plt.plot(train)
plt.plot([None for i in train] + [x for x in test])
plt.show()