from Bio import Entrez
from Bio import SeqIO
Entrez.email = "my_name@my_website.com"
id_list = set(open('pids_test.csv', 'rU'))
handle = Entrez.efetch(db="protein", rettype="fasta", retmode="text", id=id_list)	
out_handle = open("saved.fasta", "w")
for line in handle:
  out_handle.write(line)
out_handle.close()
handle.close()

Create dl_seq.py