added type annotation

src/read_sequencing.py

@@ -34,13 +34,14 @@ def read_sequencing(
     # Import classes
     from random import choices, randrange
     import numpy as np
+    from typing import List
 
     # Read data from terminal fragment file
     # Store fragments in a list
 
     f = open(frag_file_name, "r")
     frag_line = f.readline()
-    frag_list = []
+    frag_list = []  # type: List[str]
     frag_str = ""
     while frag_line != "":
         # To stop when the end of file is reached