text: Q:
  
  How to add a header for each line in pandas?
  
  I have a list of protein IDs and I want to add '>1', '>2', '>3',......'>len(list)' before each line. How can I do this in pandas?
  Example:
  protein_ID
  KKP65897.1
  KKP42119.1
  KKP91065.1
  OGY93232.1
  KUK66913.1
  
  I want it to be:
  protein_ID
  >1    
  KKP65897.1
  >2    
  KKP42119.1
  >3    
  KKP91065.1
  >4    
  OGY93232.1
  >5    
  KUK66913.1
  
  If I do this:
  for num, line in enumerate(df.protein_ID):
      print(num, line)
  
  I get:
  0 K
  1 K
  2 P
  3 6
  4 5
  5 8
  6 9
  7 7
  8 .
  9 1
  10 
  
  How can I achieve this? Thanks!
  
  A:
  
  interleave the values of protein_ID and index of df
  In [619]: from cytoolz import interleave
  
  In [620]: pd.DataFrame({'protein_ID': list(
           interleave(['>' + (df.index+1).astype(str), df.protein_ID]))})
  Out[620]:
     protein_ID
  0          >1
  1  KKP65897.1
  2          >2
  3  KKP42119.1
  4          >3
  5  KKP91065.1
  6          >4
  7  OGY93232.1
  8          >5
  9  KUK66913.1
  
  If you just need it as list
  In [625]: ['protein_ID']+list(interleave(['>' + (df.index+1).astype(str), df.protein_ID]))
  Out[625]:
  ['protein_ID',
   '>1',
   'KKP65897.1',
   '>2',
   'KKP42119.1',
   '>3',
   'KKP91065.1',
   '>4',
   'OGY93232.1',
   '>5',
   'KUK66913.1']
  
  Details
  In [621]: df
  Out[621]:
     protein_ID
  0  KKP65897.1
  1  KKP42119.1
  2  KKP91065.1
  3  OGY93232.1
  4  KUK66913.1
  
  