--- a/get_chrom_sizes/calculating_chrom.sizes.py	Wed Apr 20 15:20:33 2022 +0000
+++ b/get_chrom_sizes/calculating_chrom.sizes.py	Thu Apr 21 10:39:18 2022 +0000
@@ -3,7 +3,8 @@
 from sys import argv
 # python calculating_chrom.sizes.py genome_input.fa output.chrom.sizes
 genome = str(argv[1])
-output = str(argv[2])
+prefix = str(argv[2])
+output = str(argv[3])
 # genome = 'test-data/test.fasta'
 # output = "test-data/test_chrom.sizes"
 
@@ -20,9 +21,12 @@
 	else:
 		sequence = line.strip('\n')
 		record[1] += len(sequence)
-		
+
+if record not in records:
+	records.append(record)
+
 for seq_record in records:
-	output_line = '%s\t%i\n' % (seq_record[0], seq_record[1])
+	output_line = f"{prefix}{seq_record[0]}\t{seq_record[1]}\n"
 	chromSizesoutput.write(output_line)
 
 chromSizesoutput.close()