title: Plotting a Bar Graph in python with Matplotlib.pyplot
body: <pre><code>   Groups   Counts
  1   0-9     38
  3   10-19   41
  5   20-29   77
  7   30-39   73
  9   40-49   34
  </code></pre>
  
  <p>I want to create a bar graph using matplotlib.pyplot library with groups on x-axis and Counts on y-axis. I tried it out using following code</p>
  
  <pre><code>    ax = plt.subplots()
      rects1 = ax.bar(survived_df["Groups"], survived_df["Counts"], color='r')
      plt.show()
  </code></pre>
  
  <p>but I'm getting following error </p>
  
  <pre><code>   invalid literal for float(): 0-9
  </code></pre>