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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_sequence_lengths(fastafilenames):
 """Returns dictionary of sequence lengths, keyed by organism. Biopython's SeqIO module is used to parse all sequences in the FASTA file corresponding to each organism, and the total base count in each is obtained. NOTE: ambiguity symbols are not discounted. """

    tot_lengths = {}
    for fn in fastafilenames:
        tot_lengths[os.path.splitext(os.path.split(fn)[-1])[0]] = \
            sum([len(s) for s in SeqIO.parse(fn, 'fasta')])
    return tot_lengths