def read_peptide_input(filename):
peptides = []
metadata = []
'''expected columns (min required): id sequence'''
with open(filename, 'r') as peptide_input:
reader = csv.DictReader(peptide_input, delimiter='\t')
for row in reader:
pep = Peptide(row['sequence'])
for col in row:
if col != 'sequence':
pep.log_metadata(col, row[col])
metadata.append(col)
peptides.append(pep)
metadata = set(metadata)
return peptides, metadata
