Shortened amortization.py

Author: Nitroxium18

financial/amortization.py

@@ -1,3 +1,8 @@
+"""
+Wiki: https://en.wikipedia.org/wiki/Amortization_calculator
+"""
+
+
 def level_payment(principal, annual_rate_pct, years, payments_per_year=12):
     if principal <= 0:
         raise ValueError("principal must be > 0")
@@ -11,14 +16,7 @@ def level_payment(principal, annual_rate_pct, years, payments_per_year=12):
     return principal * (r * factor) / (factor - 1)
 
 
-def amortization_schedule(
-    principal,
-    annual_rate_pct,
-    years,
-    payments_per_year=12,
-    print_annual_summary=False,
-    eps=1e-9,
-):
+def amortization_schedule(principal, annual_rate_pct, years, payments_per_year=12, print_annual_summary=False, eps=1e-9):
     pmt = level_payment(principal, annual_rate_pct, years, payments_per_year)
     r = (annual_rate_pct / 100.0) / payments_per_year
     n = years * payments_per_year
@@ -28,9 +26,13 @@ def amortization_schedule(
 
     if print_annual_summary:
         print(
-            f"{'Year':<6}{'Months Pd':<12}{'Tenure Left':<13}{'Payment/Period':<16}{'Outstanding':<14}"
+            (
+                f"{'Year':<6}{'Months Pd':<12}{'Tenure Left':<13}"
+                f"{'Payment/Period':<16}{'Outstanding':<14}"
+            )
         )
 
+
     for period in range(1, n + 1):
         interest = balance * r
         principal_component = pmt - interest
@@ -42,22 +44,23 @@ def amortization_schedule(
         else:
             payment_made = pmt
 
-        if (
-            principal_component < 0 and principal_component > -eps
-        ):  # clamp tiny negatives
+        if principal_component < 0 and principal_component > -eps:  # clamp tiny negatives
             principal_component = 0.0
 
         balance = max(0.0, balance - principal_component)
         schedule.append([period, payment_made, interest, principal_component, balance])
 
         # streamline for all time periods (monthly/quarterly/biweekly/weekly)
-        months_elapsed = int(round((period * 12) / payments_per_year))
+        months_elapsed = (round((period * 12) / payments_per_year))
 
         if print_annual_summary and (months_elapsed % 12 == 0 or balance <= eps):
             tenure_left_periods = n - period
             print(
-                f"{months_elapsed // 12:<6}{months_elapsed:<12}{tenure_left_periods:<13}{pmt:<16.2f}{balance:<14.2f}"
+            (
+                f"{months_elapsed // 12:<6}{months_elapsed:<12}{tenure_left_periods:<13}"
+                f"{pmt:<16.2f}{balance:<14.2f}"
             )
+        )
 
         if balance <= eps:
             break
@@ -69,7 +72,5 @@ def amortization_schedule(
     return round(pmt, 4), schedule
 
 
-pmt, sched = amortization_schedule(
-    10000, 5.5, 15, payments_per_year=12, print_annual_summary=True
-)
+pmt, sched = amortization_schedule(10000, 5.5, 15, payments_per_year=12, print_annual_summary=True)
 print(pmt)