Iterate over a fasta with a single sequence in

gistfile1.py

@contextlib.contextmanager
def fasta_sequence(file):
    with open(file, 'r') as f:
        f.next() #loose the header row
        def generator():
            for line in f:
                for char in line.strip():
                    yield char
        yield generator()


use like:
with fasta_sequence(file) as seq:
    for base in seq:
        print base