Correct calculate_transaction

abrechnung/group.py

@@ -1,6 +1,7 @@
 # vim: tabstop=2 expandtab shiftwidth=2 softtabstop=2
 import random, copy, time
 import transaction as trans
+import utils as u
 import operator
 
 class Group:
@@ -141,12 +142,12 @@ def calculate_balancing(self):
         if pos.balance != 0:
           if pos.balance >= -neg.balance:
             #There is enough credit on the pos so neg has to transfer all to him
-            transaction_list.append(trans.Transaction(str(-neg.balance), neg.name, pos.name))
+            transaction_list.append(trans.Transaction(u.amount_to_string(-neg.balance), neg.name, pos.name))
             pos.balance += neg.balance
             neg.balance = 0
           else:
             #There is not enough credit on pos so neg has to transfer a part to him
-            transaction_list.append(trans.Transaction(str(pos.balance), neg.name, pos.name))
+            transaction_list.append(trans.Transaction(u.amount_to_string(pos.balance), neg.name, pos.name))
             neg.balance += pos.balance
             pos.balance = 0
 

abrechnung/utils.py

@@ -24,6 +24,22 @@ def levenshtein(s1, s2):
 
   return previous_row[-1]
 
+
+def amount_to_string(amount):
+  negative = amount < 0
+  if negative:
+    amount *= -1
+
+  fractional_part = amount % 100
+  integer_part = (amount - fractional_part) // 100
+
+  ret = "{}.{:02d}".format(integer_part, fractional_part)
+  if negative:
+    ret = "-" + ret
+
+  return ret
+
+
 def parse_amount(s):
   try:
     return try_parse_with_delim(s, '.')