diff --git a/src/poly_a.py b/src/poly_a.py
index b04574470c1bb290fd35f22fb83949563f390e3a..6ca8baf9f7a7a41d7e114edae89adb673ac0f665 100644
--- a/src/poly_a.py
+++ b/src/poly_a.py
@@ -72,13 +72,12 @@ def generate_poly_a(
 
 
 def main():
-    """Append poly A tails to fasta sequences and write to file
-    
-    This function iterates over `input` fasta sequences from a specified file, 
-    appends tails of given `length` and composition specified by `weights`, 
+    """Append poly A tails to fasta sequences and write to file.
+
+    This function iterates over `input` fasta sequences from a specified file,
+    appends tails of given `length` and composition specified by `weights`,
     and writes them to file specified as `output`.
     """
-
     parser = argparse.ArgumentParser(description='Process some integers.')
     parser.add_argument('-i', '--input', required=True,
                         help='Fasta file to add tails to')
@@ -91,7 +90,7 @@ def main():
     args = parser.parse_args()
 
     new_records = []
-    for fasta in SeqIO.parse(open(args.input),'fasta'):
+    for fasta in SeqIO.parse(open(args.input), 'fasta'):
         new_seq = fasta.seq + Seq(generate_poly_a(args.length, args.weights))
         new_records.append(SeqRecord(new_seq, id=fasta.id, description=fasta.description))
     SeqIO.write(new_records, args.output, "fasta")