title: Matplotlib Legend not showing on subplots
body: <p>I can't get the legends to show on the subplots which show up just fine and take the other formatting I've applied.  What am I missing?</p>
  
  <p>If I do a plot for the dataframe alone, it shows the legend.  If I add a label to the plot for the subplots, it assigns that label to all three lines.</p>
  
  <p>Here is image. plot vs subplot</p>
  
  <p><img src="https://i.stack.imgur.com/FvBTv.gif" alt=""></p>
  
  <pre><code>import pandas as pd
  import numpy as np
  import matplotlib.pyplot as plt
  import matplotlib.ticker as ticker
  from functools import reduce
  
  %matplotlib notebook
  
  #Source for files
  # Per Capita Personal Income
  # Ann Arbor https://fred.stlouisfed.org/series/ANNA426PCPI
  # MI https://fred.stlouisfed.org/series/MIPCPI
  # USA https://fred.stlouisfed.org/series/A792RC0A052NBEA
  
  dfAnnArbor_PCPI = pd.read_csv('PerCapitaPersonalIncomeAnnArborMI.csv', skiprows=1, names=['Date', 'PCPI'])
  dfMI_PCPI = pd.read_csv('PerCapitaPersonalIncomeMI.csv', skiprows=1, names=['Date', 'PCPI'])
  dfUSA_PCPI = pd.read_csv('PerCapitaPersonalIncomeUSA.csv', skiprows=1, names=['Date', 'PCPI'])
  
  # consolidate three df into one using Date
  dfAll = [dfAnnArbor_PCPI, dfMI_PCPI, dfUSA_PCPI]
  dfPCPI = reduce(lambda left, right: pd.merge(left, right, on='Date', how='outer'), dfAll)
  
  dfPCPI = dfPCPI.dropna() # drop rows with NaN
  dfPCPI.columns = ['Date', 'AnnArbor', 'MI', 'USA'] # rename columns
  dfPCPI['Date'] = dfPCPI['Date'].str[:4] # select only year
  dfPCPI = dfPCPI.set_index('Date')
  
  dfPCPI_Rel = dfPCPI.apply(lambda x: x / x[0])
  
  dfPCPI_Small = dfPCPI.iloc[8:].copy()
  dfPCPI_SmRel = dfPCPI_Small.apply(lambda x: x / x[0])
  
  dfPCPI_SmRel.plot()
  
  fig, ax = plt.subplots(1, 2)
  
  ax0 = ax[0].plot(dfPCPI_Rel, '-', label='a')
  ax1 = ax[1].plot(dfPCPI_SmRel, '-', label='test1')
  
  ax[0].legend()
  
  for x in fig.axes:
      for label in x.get_xticklabels():
          label.set_rotation(45)
  
  ax[1].xaxis.set_major_locator(ticker.MultipleLocator(2))
  
  plt.show()
  </code></pre>