title: How to add black border to matplotlib 2.0 `ax` object In Python 3?
body: <p>I've been using style sheets in <code>matplotlib</code> lately.  I really like how clean the <code>seaborn-white</code> looks and I want to be able to add the border to other styles like <code>ggplot</code> or <code>seaborn-whitegrid</code>.</p>
  
  <p><strong>How can I add a black border around my <code>ax</code> object from <code>fig, ax = plt.subplots()</code>?</strong> </p>
  
  <pre><code>import pandas as pd
  import numpy  as np
  from collections import *
  
  Se_data = pd.Series(Counter(np.random.randint(0,10,100)))
  with plt.style.context("seaborn-whitegrid"):
      fig, ax = plt.subplots()
      Se_data.plot(kind="barh", ax=ax, title="No Border")
  with plt.style.context("seaborn-white"):
      fig, ax = plt.subplots()
      Se_data.plot(kind="barh", ax=ax, title="With Border")
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/om8rA.png" rel="noreferrer"><img src="https://i.stack.imgur.com/om8rA.png" alt="enter image description here"></a></p>
  
  <p>In response to the answer below: </p>
  
  <pre><code>Se_data = pd.Series(Counter(np.random.randint(0,10,100)))
  with plt.style.context("seaborn-whitegrid"):
      fig, ax = plt.subplots()
      Se_data.plot(kind="barh", ax=ax, title="No Border")
      ax.spines['bottom'].set_color('0.5')
      ax.spines['top'].set_color(None)
      ax.spines['right'].set_color('0.5')
      ax.spines['left'].set_color(None)
      ax.patch.set_facecolor('0.1')
      plt.grid(b=True, which='major', color='0.2', linestyle='-')
      plt.grid(b=True, which='minor', color='0.2', linestyle='-')
      ax.tick_params(axis='x', colors='0.7', which='both')
      ax.tick_params(axis='y', colors='0.7', which='both')
      ax.yaxis.label.set_color('0.9')
      ax.xaxis.label.set_color('0.9')
      ax.margins(5)
      fig.patch.set_facecolor('0.15')
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/z0Exh.png" rel="noreferrer"><img src="https://i.stack.imgur.com/z0Exh.png" alt="enter image description here"></a></p>