make more robust against data error

parsers/survex.py

@@ -22,6 +22,12 @@ It also scans the Loser repo for all the svx files, which it loads individually
 """
 
 todo = """
+- Rewrite regexes to use .groupdict instead of .group, 
+  easier to understand and maintain
+  https://mathspp.com/blog/til/re-match-groupdict
+  
+- replace hard-coded instuments list with reding an editable textfile in expoweb.
+
 - Obscure bug in the *team inheritance and rootblock initialization needs tracking down,
   probably in the team cache which should NOT be global, but should be an instance variable of 
   LoadingSurvex
@@ -75,10 +81,6 @@ class SurvexLeg:
     clino = 0.0
     
         
-
-
-
-
 def datewallet(w, earliest):
     """Gets the date of the youngest survexblock associated with the wallet
     REFACTOR this to do the whole date-getting task
@@ -163,7 +165,7 @@ def get_people_on_trip(survexblock):
     
     return list(set(people))
 
-# THIS SHOULD NOT BE GLOBAL ! SHould be per instance of file loader
+# THIS SHOULD NOT BE GLOBAL ! Should be per instance of file loader
 trip_person_record = {}  # indexed by (survexblock, personexpedition) - so never needs cleaning out
 trip_team_cache = {}  #  indexed by  survexblock, so never needs cleaning out
 def put_person_on_trip(survexblock, personexpedition, tm):