paste_david.py

def extract_proteinid(description):
    splitted = description.split(" ")


    for feature in splitted:
        if "protein_id" in feature:
            print(feature.split("=")[1][:-1])
            
            
for seq_nucleotides in SeqIO.parse("CDS_sequence.txt", "fasta"):
    extract_proteinid(seq_nucleotides.description)
    print(seq_nucleotides.seq)