from collections import OrderedDict, Counter x= [12, 127, 28, 42, 39, 113, 42, 18, 44, 118, 44, 37, 113, 124, 37, 48, 127, 36, 29, 31, 125, 139, 131, 115, 105, 132, 104, 123, 35, 113, 122, 42, 117, 119, 58, 109, 23, 105, 63, 27, 44, 105, 99, 41, 128, 121, 116, 125, 32, 61, 37, 127, 29, 113, 121, 58, 114, 126, 53, 114, 96, 25, 109, 7, 31, 141, 46, 13, 27, 43, 117, 116, 27, 7, 68, 40, 31, 115, 124, 42, 128, 52, 71, 118, 117, 38, 27, 106, 33, 117, 116, 111, 40, 119, 47, 105, 57, 122, 109, 124, 115, 43, 120, 43, 27, 27, 18, 28, 48, 125, 107, 114, 34, 133, 45, 120, 30, 127, 31, 116, 146] def stemleaf(x): d = OrderedDict((((str(v)[:-1],' ')[v<10], Counter()) for v in sorted(x))) for s in ((str(v),' '+str(v))[v<10] for v in x) : d[s[:-1]][s[-1]]+=1 m=max(len(s) for s in d) for k in d: print('%s%s | %s'%(' '*(m-len(k)),k,' '.join(sorted(d[k].elements())))) stemleaf(x)