title: How to repeat values in a new Column in Pandas if condition
body: <p>I have a dataframe like this:</p>
  <pre><code>
  Index     Category   Sales   
  01-01-21    Blue     83.20  
  01-02-21    Yellow   98.57  
  01-03-21    Green    55.70  
  01-04-21    Orange   87.32  
  01-05-21    Black    65.02  
  01-06-21    Yellow   61.05  
  01-07-21    White    10.54  
  01-08-21    Yellow   73.59  
  01-09-21    Blue     13.88  
  01-10-21    Black    47.39  
  01-11-21    Blue     55.75  
  01-12-21    Yellow   39.64  
  01-01-22    Green    39.64  
  01-02-22    Orange   39.64  
  01-03-22    Black    28.87    
  01-04-22    Yellow   82.40   
  01-05-22    White    28.09    
  01-06-22    Yellow   74.64  
  01-07-22    Blue     18.27   
  01-08-22    Black    11.16    
  01-09-22    Green    79.49  
  01-10-22    Green    46.74    
  01-11-22    Yellow   6.81    
  01-12-22    Blue     8.00    
  
  </code></pre>
  <p>I want to add a new column repeating the values of Sales for Oct, Nov and Dec into the next 12 months. So the result will looks like this:</p>
  <pre><code>Index   Category     Sales   New Column 
  01-01-21    Blue     83.20  
  01-02-21    Yellow   98.57  
  01-03-21    Green    55.70  
  01-04-21    Orange   87.32  
  01-05-21    Black    65.02  
  01-06-21    Yellow   61.05  
  01-07-21    White    10.54  
  01-08-21    Yellow   73.59  
  01-09-21    Blue     13.88  
  +--------------------------------------------+
  01-10-21    Black    47.39  
  01-11-21    Blue     55.75  
  01-12-21    Yellow   39.64  
  +--------------------------------------------+
  01-01-22    Green    39.64   47.39 
  01-02-22    Orange   39.64   55.75 
  01-03-22    Black    28.87   39.64 
  01-04-22    Yellow   82.40   47.39 
  01-05-22    White    28.09   55.75 
  01-06-22    Yellow   74.64   39.64 
  01-07-22    Blue     18.27   47.39 
  01-08-22    Black    11.16   55.75 
  01-09-22    Green    79.49   39.64 
  01-10-22    Green    46.74   47.39 
  01-11-22    Yellow   6.81    55.75 
  01-12-22    Blue     8.00    39.64 
  </code></pre>
  <p>I have tried in this way:</p>
  <pre><code>recurr_oct = new.loc[new.index.isin(['01-10-21']), 'Sales'].values
  recurr_nov = new.loc[new.index.isin(['01-11-21']), 'Sales'].values
  recurr_dec = new.loc[new.index.isin(['01-12-21']), 'Sales'].values
  
  new.index = pd.to_datetime(new.index)
  rating = []
  for row in new.index.month:
      if row == 1 or row == 4 or row == 7 or row == 10:    rating.append(recurr_oct)
      elif row == 2 or row == 5 or row == 8 or row == 11:   rating.append(recurr_nov)
      elif row == 3 or row == 6 or row == 9 or row == 12:  rating.append(recurr_dec)
      else: rating.append(0)
          
  new['New Column'] = rating
  new.head()
  </code></pre>
  <p>but it takes time and it does not looks that good, is there a better way to do it?</p>
  <p>Thanks!</p>