itertools

 1 from itertools import groupby
 2 def compress(data):
 3  return ((len(list(group)),name)
 4   for name,group in groupby(data))
 5 def decompress(data):
 6  return (car*size for size,car in data)
 7 if __name__ == ‘__main__‘:
 8  l=list(compress(‘get uuuuuuuuuuuuuuuup‘))
 9  print l
10  print ‘‘.join(decompress(l))