title: Python error: generating a scatter plot using matplotlib
body: <p>
  I am a python newbie suffering from how to import CSV file in matplotlib.pyplot
  I would like to see the relationship between hour (=how many hours people spent to play a video game) and level (=game level). and then I would like to draw a scatter plot with Tax in different colors between female(1) and male(0).So, my x would be 'hour' and my y would be 'level'. </p>
  
  <p>my data csv file looks like this:</p>
  
  <pre><code>          hour gender level
  0            8    1   20.00
  1            9    1   24.95
  2           12    0   10.67
  3           12    0   18.00
  4           12    0   17.50
  5           13    0   13.07
  6           10    0   14.45
  ...
  ...
  499         12    1  19.47
  500         16    0  13.28
  </code></pre>
  
  <p>
  Here's my code:</p>
  
  <pre><code>import matplotlib.pyplot as plt
  import numpy as np
  import pandas as pd
  
  df=pd.read_csv('data.csv')
  plt.plot(x,y, lavel='some relationship')
  plt.title("Some relationship")
  plt.xlabel('hour')
  plt.ylabel('level')
  plt.plot[gender(gender=1), '-b', label=female]
  plt.plot[gender(gender=0), 'gD', label=male]
  plt.axs()
  plt.show()
  </code></pre>
  
  <p>
  I would like to draw the following graph. So, there will be two lines of male and female. </p>
  
  <pre><code>y=level|           @-----&gt;male
         | @
         | *         *-----&gt;female
         |________________ x=hour
  </code></pre>
  
  <p>
  However, I am not sure how to solve this problem. 
  I kept getting an error NameError: name 'hour' is not defined. </p>