Polish

Trajectories/filter_traj.py

 #!/usr/bin/env python3
 
+"""This script reads a Json file containing expanded trajectories. It
+writes a new Json file containing truncated trajectories. Each
+truncated trajectory contains only eddies before a given date.
+
+"""
+
 import json
 import bisect
 import sys
@@ -10,8 +16,10 @@ if len(sys.argv) != 4:
     sys.exit("Required arguments: last-date input-file output-file")
 
 last_date = int(sys.argv[1])
+
 with open(sys.argv[2]) as f:
     expanded_traj = json.load(f)
+
 last_node = util_eddies.date_eddy_to_node(
     last_date, expanded_traj["e_overestim"], expanded_traj["e_overestim"]
 )