def trimLens(lens, minLen):
 index = 0
 for i in range(len(lens)):
  if (lens[i] < minLen):
   index += 1
  else:
   break
 return lens[index:len(lens)]

def trimLens ( lens , minLen ) : index = 0 for i in range ( len ( lens ) ) : if ( lens [ i ] < minLen ) : index += 1 else : break return lens [ index : len ( lens ) ]
eliminates any reads below a certain threshold .