title: Not able to create a 3x3 grid of subplots to visualize 9 Series individually
body: <p>I want to have a 3x3 grid of subplots to visualize each Series individually.
  I first created some toy data:</p>
  <pre><code>import numpy as np
  import pandas as pd
  import seaborn as sns
  import matplotlib.pyplot as plt
  sns.set(style='whitegrid', rc={&quot;figure.figsize&quot;:(14,6)})
  
  rs = np.random.RandomState(444)
  dates = pd.date_range(start=&quot;2009-01-01&quot;, end='2019-12-31', freq='1D')
  values = rs.randn(4017,12).cumsum(axis=0)
  data = pd.DataFrame(values, dates, columns =['a','b','c','d','e','f','h','i','j','k','l','m'])
  </code></pre>
  <p>Here is the first code I wrote:</p>
  <pre><code>fig, ax = plt.subplots(3, 3, sharex=True, sharey=True)
  for col in n_cols:
      ax = data[col].plot()
  </code></pre>
  <p>With these lines of code the problem is that I get the 3x3 grid but all the columns have been plotten on the same subplotsAxes, in the bottom right corner.
  <a href="https://i.stack.imgur.com/Ppl6j.png" rel="nofollow noreferrer">Bottom Right Corner with all Lines</a></p>
  <p>Here is the second thing I tried:</p>
  <pre><code>n_cols = ['a', 'b', 'c', 'd', 'e', 'f', 'h', 'i', 'j']
  fig, ax = plt.subplots(3, 3, sharex=True, sharey=True)
  for col in n_cols:
      for i in range(3):
          for j in range(3):
              ax[i,j].plot(data[col])
  </code></pre>
  <p>But now I get all the columns plotted on every single subplotAxes.
  <a href="https://i.stack.imgur.com/bFVVk.png" rel="nofollow noreferrer">All AxesSubplot with same lines</a></p>
  <p>And if I try something like this:</p>
  <pre><code>fig, ax = plt.subplots(sharex=True, sharey=True)
  for col in n_cols:
      for i in range(3):
          for j in range(3):
              ax[i,j].add_subplot(data[col])
  </code></pre>
  <p>But I get:
  TypeError: 'AxesSubplot' object is not subscriptable</p>
  <p>I am sorry but can't figure out what to do.</p>