title: Plotting multiple lines in one graph with time in months on the x-axis, number of occurences on the y-axis
body: <p>I'm currently working on a movie dataset, which I have filtered to the number of watches per day per genre. I have filtered it to a dataframe as follows:</p>
  
  <p>I created a dataframe with 2 columns (besides the index), namely <code>'Date'</code> and <code>'Genre'</code>. The datatypes are <code>datetime64[ns]</code> and <code>'Genre'</code> is an <code>object</code>.</p>
  
  <p>To visualize this:</p>
  
  <pre><code>Date           Genre
  2018-01-01     romance
  2018-01-01     fiction
  2018-01-01     romance
  2018-01-02     drama
  2018-01-02     romance
  2018-01-02     fiction    
  2018-01-02     romance
  2018-01-03     romance
  2018-01-03     drama
  </code></pre>
  
  <p>The list goes on (whole 2018) and it shows that, based on the dataset, on 2018-01-01 three movies have been watched in the <code>Genre</code> romance, fiction, and romance. </p>
  
  <p><strong>Question:</strong></p>
  
  <p>I want to plot a multiple line graph, in which each line represents a different genre. On the x-axis, the time will be displayed in months and on the y-axis, the number of watches will be displayed. What I'm trying to  do, is plot each genre in the same graph and show the number of watches of that genre per day, where the x-axis is labeled in months.</p>
  
  <p>What I've tried so far:</p>
  
  <p>Sorting the movie dataframe per genre and store it in a new variable:</p>
  
  <pre><code>df_2018_rom = df_movies_2018[df_movies_2018.Genre == 'romance']
  .groupby(['Genre', 'Date']).Date.count()
  </code></pre>
  
  <p>But I still can't seem to plot the graph I want. </p>
  
  <p>Thanks for any help in advance!</p>