simplified when we calc totals and hence growth, applied monthly growth annually

bills.py

@@ -35,11 +35,13 @@ def add_missing_monthly_bills_in_yr( bill_type, bill_info, yr ):
     # really perfectly the same each month, but its only for an estimate so should be ok
     dd = bill_info[bill_type]['first_bill']['bill_date'][8:]
     mm = bill_info[bill_type]['first_bill']['bill_date'][5:7]
+    lb_mm = bill_info[bill_type]['last_bill']['bill_date'][5:7]
 
     # choose last bill from last amount to grow from as its most relevant
-    amt = bill_info[bill_type]['last_bill']['amount']
+    if not 'last_bill_amount' in bill_info[bill_type]:
+        bill_info[bill_type]['last_bill_amount']=bill_info[bill_type]['last_bill']['amount']
+    amt = bill_info[bill_type]['last_bill_amount']
 
-    growth=0
     #okay add monthly bills for the rest of this year if its the first year
     if bill_info[bill_type]['first_bill_year'] == yr:
         start_m=int(mm)
@@ -59,7 +61,12 @@ def add_missing_monthly_bills_in_yr( bill_type, bill_info, yr ):
                     bill_found=True
                     break
         if not bill_found:
-            amt += amt * growth/100
+            # if this month is the same as the last bill month and as per above
+            # we don't have a bill for this date, then add annual grotwh
+            if i == int(lb_mm):
+                print(f"its month: {i} - time to add growth: {bill_info[bill_type]['growth']}" )
+                amt += amt * bill_info[bill_type]['growth']/100
+                bill_info[bill_type]['last_bill_amount']=amt
             # last param is estimated (and this is an estimate for a future bill / not real)
             new_bill( bill_type, amt, new_date, 1 )
     return
@@ -94,6 +101,9 @@ def process_bill_data(bd, bt, bf):
             # due to sql sorting, this first instance is the last bill
             bill_info[bill_type]['last_bill']=bill
             bill_info[bill_type]['last_bill_year']=int(bill['bill_date'][:4])
+            if not bill['estimated']:
+                print( f"this bill is real, its the first so consider it the last bill paid - date is: {int(bill['bill_date'][:4])}" )
+                bill_info[bill_type]['last_real_bill_year']=int(bill['bill_date'][:4])
             bill_info[bill_type]['year']={}
             bill_info[bill_type]['year_real']={}
         if not yr in bill_info[bill_type]['year']:
@@ -103,6 +113,9 @@ def process_bill_data(bd, bt, bf):
         # keep updating last to this matching bill
         bill_info[bill_type]['first_bill']=bill
         bill_info[bill_type]['first_bill_year']=int(bill['bill_date'][:4])
+        if not 'last_real_bill_year' in bill_info[bill_type] and not bill['estimated']:
+            print( f"{bill_type}: seems we dont have a last_real_bill_year, set it to: {int(bill['bill_date'][:4])} ")
+            bill_info[bill_type]['last_real_bill_year']=int(bill['bill_date'][:4])
         # add this bill to list for this year
         bill_info[bill_type]['year'][yr].append(bill)
         if not bill['estimated']:
@@ -142,11 +155,20 @@ def add_missing_bills_for_yr( bill_type, bill_info, yr ):
     return
 
 def derive_ann_growth( bill_type, bill_info ):
-    print(f"{bill_type}: Derive annual growth on bill_type: {bill_type} " )
+    print(f"{bill_type}: Derive annual growth on bill_type: {bill_type} - fby={bill_info[bill_type]['first_bill_year']}, lby={bill_info[bill_type]['last_real_bill_year']} " )
 
     total={}
-    for yr in range( bill_info[bill_type]['first_bill_year'], bill_info[bill_type]['last_bill_year']+1):
+    for yr in range( bill_info[bill_type]['first_bill_year'], bill_info[bill_type]['last_real_bill_year']+1):
-        if len(bill_info[bill_type]['year_real'][yr]) != bill_info[bill_type]['num_ann_bills']:
+        # for monthly bills, 1 or 12 bills is enough to work with
+        if bill_info[bill_type]['num_ann_bills'] == 12:
+            if len(bill_info[bill_type]['year_real'][yr]) != 1 and len(bill_info[bill_type]['year_real'][yr]) != 12:
+                continue;
+        # okay annual or quarterly bills, only total them if we have all of them for the year
+        elif len(bill_info[bill_type]['year_real'][yr]) != bill_info[bill_type]['num_ann_bills']:
+            continue;
+
+        # for monthlys add totals regardless (we only process total if there is 12 or 1 further below).  Other bill_types, only total if there is all bills for year
+        if bill_info[bill_type]['num_ann_bills'] != 12 and len(bill_info[bill_type]['year_real'][yr]) != bill_info[bill_type]['num_ann_bills']:
             continue
         total[yr] = 0
         for b in bill_info[bill_type]['year'][yr]:
@@ -161,15 +183,9 @@ def derive_ann_growth( bill_type, bill_info ):
     avg_growth = 0
     max_growth = 0
     count = 0
-    for yr in range( bill_info[bill_type]['first_bill_year'], bill_info[bill_type]['last_bill_year']+1):
+    # start from year after first bill, so we can see annual growth from the following year onwards
-        # less than {num_ann_bills} bills in yr: {yr-1}, so can't use data
+    for yr in range( bill_info[bill_type]['first_bill_year']+1, bill_info[bill_type]['last_bill_year']+1):
-        if yr-1 in bill_info[bill_type]['year'] and len(bill_info[bill_type]['year'][yr-1]) != bill_info[bill_type]['num_ann_bills']:
+        # if full data sets for consecutive years, work out annual growth stats
-            continue
-        # less than {num_ann_bills} bills in yr: {yr-1}, so can't use data
-        if yr in bill_info[bill_type]['year'] and len(bill_info[bill_type]['year'][yr]) != bill_info[bill_type]['num_ann_bills']:
-            continue
-
-        # we full data sets for consecutive years, work out annual growth stats
         if yr-1 in total and yr in total:
             growth = (total[yr] - total[yr-1]) / total[yr-1] * 100
             avg_growth += growth