add survey by year to wallets for each cave: Charlotte's request

core/models/survex.py

@@ -246,6 +246,12 @@ class SurvexBlock(models.Model):
 
     def isSurvexBlock(self):  # Function used in templates
         return True
+        
+    def year(self):
+        if self.date:
+            return self.date.year
+        else:
+            return 1970
 
     def DayIndex(self):
         """This is used to set different colours for the different trips on

core/views/scans.py

@@ -1,4 +1,5 @@
 import datetime
+from collections import defaultdict
 from pathlib import Path
 from urllib.parse import unquote as urlunquote
 
@@ -327,14 +328,25 @@ def cavewallets(request, caveid):
 
     expeditions = Expedition.objects.all()
     length_ug = 0.0
+    length_by_year = defaultdict(int) # initialises values to zero
+    checksum = 0
     for w in manywallets:
         for sb in w.survexblock_set.all():
             length_ug += sb.legslength    
+            length_by_year[sb.year()] += sb.legslength
+    length_by_year = dict(sorted(length_by_year.items())) 
+    for y in length_by_year:
+        checksum += length_by_year[y]
+        print(f"{y} {length_by_year[y]:.0f}")
+    for key in list(length_by_year.keys()):
+        if length_by_year[key] < 0.1:
+            del length_by_year[key]
+            
     return render(
         request,
         "cavewallets.html",
         {"manywallets": manywallets, "settings": settings, "cave": cave, "expeditions": expeditions,
-        "length_ug": length_ug, "year": current_expo()}
+        "length_ug": length_ug, "length_by_year": length_by_year, "checksum": checksum, "year": current_expo()}
     )