>>> from Bio.Alphabet import IUPAC
>>> seq1 = Seq.Seq("MMSARGDFLN", IUPAC.protein)
>>> seq2 = Seq.Seq("YALSLMRSHN", IUPAC.protein)
>>> seq = seq1 + seq2
>>> print seq
Seq('MMSARGDFLNYALSLMRSHN', IUPACProtein())
>>> print seq[0]
M
>>> print seq[:5]
Seq('MMSAR', IUPACProtein())
>>> print seq[-3:]
Seq('SHN', IUPACProtein())
>>> print seq.data
MMSARGDFLNYALSLMRSHN
>>>