Merge branch 'master' into publish

minor, "an" to "a"

src/amort.py

@@ -1,5 +1,5 @@
 
-def generate_amortization_schedule(principal, interest_rate, loan_term, events=[]):
+def generate_amortization_schedule(principal, interest_rate, loan_term, extra_payments=[]):
     # Convert interest rate to decimal and calculate periodic interest rate
     monthly_interest_rate = interest_rate / 12 / 100
 
@@ -15,9 +15,8 @@ def generate_amortization_schedule(principal, interest_rate, loan_term, events=[
     amortization_schedule = []
 
     one_time_payment = None
-    if events != []:
-        one_time_payment = events["extra-payments"].pop(0)
-
+    if extra_payments != []:
+        one_time_payment = extra_payments.pop(0)
     for payment_number in range(1, num_payments + 1):
         # Calculate interest for the current period
         if remaining_balance == 0:
@@ -30,8 +29,8 @@ def generate_amortization_schedule(principal, interest_rate, loan_term, events=[
         # Apply one-time payment if provided
         if one_time_payment and payment_number == one_time_payment['payment-number']:
             principal_payment += one_time_payment['amount']
-            if events["extra-payments"] != []:
-                one_time_payment = events["extra-payments"].pop(0)
+            if extra_payments != []:
+                one_time_payment = extra_payments.pop(0)
         # Update remaining balance
         remaining_balance -= principal_payment
 
@@ -58,7 +57,8 @@ def get_totals(amortization_schedule, func=None):
     # Display the amortization schedule
     messages = []
     for payment in amortization_schedule:
-        # total_paid += payment["Payment Amount"]
+        # print(payment)
+        total_paid += payment["Payment Amount"]
         total_interest_paid += payment["Interest Payment"]
         total_principal_paid += payment["Principal Payment"]  
         if payment["Remaining Balance"] < 0:
@@ -68,9 +68,7 @@ def get_totals(amortization_schedule, func=None):
             messages.append("%s" % ", ".join([str(attr) for attr in attrs]))
     if func is not None:
         func(messages)
-    return ((total_interest_paid + total_principal_paid), 
-            total_interest_paid, 
-            total_principal_paid)
+    return total_paid, total_interest_paid, total_principal_paid
 
 def compare(with_extra_payments, without):
     x,y,z = get_totals(with_extra_payments)
@@ -81,40 +79,20 @@ def compare(with_extra_payments, without):
     print(chr(916), "principal paid: ", round(abs(z-c),2))
     print(chr(916), "term (months): ", term_length)
 
-def whatif(events, x = 500, terms = 120):
-    """
-    What if I paid an extra x dollars each term.
-    Parameters:
-        x     = amount to pay
-        terms = total expected terms
-    """
-    key_list = "extra-payments"
-    key_attr1 = "payment-number"
-    key_attr2 = "amount"
-    # get the last payment number from events
-    latest = events[key_list][-1][key_attr1]
-    start  = latest + 1
-    for i in range(start, 120):
-        new_event = dict()
-        new_event[key_attr1] = i
-        new_event[key_attr2] = x
-        events[key_list].append(new_event)
-    return events, start
-
 def display(table):
-    print("id, due, interest payment, principal payment, remaining")
+    print("id, paid, interest payment, principal payment, remaining")
     for row in table:
         print(row)
 
 def export(table, filename="schedule.csv"):
     with open(filename, 'w') as f:
-        print("id, due, interest payment, principal payment, remaining", file=f)
+        print("id, paid, interest payment, principal payment, remaining", file=f)
         for row in table:
             print(row, file=f)
     print("wrote to file", filename)
 
 if __name__ == "__main__":
-    import argparse, json, copy
+    import argparse, json
 
     def get_arguments():
         p = argparse.ArgumentParser()
@@ -125,59 +103,33 @@ if __name__ == "__main__":
         p.add_argument("--term", "-t", type=int,\
             help="sets the term (years)")
         p.add_argument("--one-time", "-ot", type=str,\
-            help="a one-time payment (json, example: {\"payment-number\":13,\"amount\":5000}")
-        p.add_argument("--events", "-e", type=str,\
-            help="name of .json file containing events such as one-time payments or interest rate changes")
+            help="factors in a one-time payment (json, example: {\"payment-number\":13,\"amount\":5000}")
+        p.add_argument("--extra-payments", "-ep", type=str,\
+            help="facts in multiple one time payments (json file name)")
         args = p.parse_args()
         l = []
-        if args.events is not None:
-            with open(args.events) as f:
+        if args.extra_payments is not None:
+            with open(args.extra_payments) as f:
                 l = json.loads(f.read())
+        extra = []
+        if "extra-payments" in l:
+            extra = l["extra-payments"]
+            extra.sort(key=lambda k: k["payment-number"])
         if args.one_time is not None:
-           l["extra-payments"].append(json.loads(args.one_time))
-        return args.principal, args.interest_rate, args.term, l
+            extra.append(json.loads(args.one_time))
+        return args.principal, args.interest_rate, args.term, extra
 
-    def main():
-        principal, interest_rate, loan_term, events = get_arguments()
+    principal, interest_rate, loan_term, extra_payments = get_arguments()
+
+    schedule = generate_amortization_schedule(principal, interest_rate, loan_term, extra_payments)
+    paid, interest_paid, principal_paid = get_totals(schedule,export)
+
+    print("total paid: ", round(paid,2))
+    print("total interest paid: ", round(interest_paid,2))
+    print("total principal paid: ", round(principal_paid,2))
+
+    # without extra payments for comparison
+    compare(schedule, generate_amortization_schedule(
+        principal, interest_rate, loan_term)
+    )
 
-        wi_start = 0
-        wi_x     = 500
-        if events:
-            # the amount paid ahead canonically
-            ahead_paid = sum(pay["amount"] for pay in events["extra-payments"])
-            ahead_msg  = f"total extra payments: {ahead_paid}"
-            border = "~" * len(ahead_msg)
-            print(border)
-            print(ahead_msg)
-            print(border)
-            events, wi_start = whatif(events, x=wi_x)
-        # generate the schedule
-        schedule = generate_amortization_schedule(
-            principal, interest_rate, loan_term, copy.deepcopy(events)
-        )
-        paid, interest_paid, principal_paid = get_totals(schedule,export)
-        # report on schedule
-        print("total paid: ", round(paid,2))
-        print("total interest paid: ", round(interest_paid,2))
-        print("total principal paid: ", round(principal_paid,2))
-        # get the last term of the schedule
-        if events:
-            wi_end = schedule[-1]["Payment Number"]
-            wi_paid = sum(
-                pay["amount"] for pay in \
-                    events["extra-payments"][wi_start:wi_end]
-            )
-            wi_msg = f"total if {wi_x} was also paid each term: {wi_paid}"
-            border = '~' * len(wi_msg)
-            print(border)
-            print(wi_msg)
-            print(border)
-            # without extra payments for comparison
-            compare(schedule, generate_amortization_schedule(
-                principal, interest_rate, loan_term)
-            )
-        print()
-    # with open("extra_payments.json") as f:
-    #     e = json.load(f)
-    # print(whatif(e))
-    main()