Refactored Age Calculation Logic with Improved Date Handling

Desktop Application/Basic/Python/Age calculator/age.py

@@ -1,33 +1,40 @@
 import datetime
+
+# Get the current system date and time
 now = datetime.datetime.now()
-key1 = now.year - 18
-key3 = now.month
-d1 = datetime.date.today()
-num = 0
+
 try:
-    birthday = input("When is your birthday?")
-    birthday = datetime.datetime.strptime(birthday,"%d/%m/%Y",).date()
-    key2 = birthday.year+18
-    age = now.year - birthday.year
-    b_month = birthday.month
-    n_year = now.year
-    b_year = birthday.year
-######################################################################################################################################################################
-    while b_year < n_year:
-        year1 = 12                          # 1 year = 12 months
-        num = num + 1
-        b_year = b_year + 1
-    num2 = 12 - b_month
-    months = num * 12 + num2 - 1
-    days = now.day - birthday.day
-    # print(days)
-#######################################################################################################################################################################
-    if birthday <= datetime.date.today() and key2 <= now.year:
-        print("Your birthday is "+ birthday.strftime('%d, %B %Y'), "and Your Age is", age, "years and", num2-1,"months and", days, "days")
-    elif age < 0:
-        print("Date or format is incorrect")
-    else:
-        print("You are under 18", "and Your Age is", age, "years and", num2-1,"months and", days, "days")
-except:
-    print("date or format is invalid")
-25
+    # Take user input of their birth date
+    birthday = input("When is your birthday? (dd/mm/yyyy): ")
+    birthday = datetime.datetime.strptime(
+        birthday,
+        "%d/%m/%Y",
+    ).date()
+
+    # Calculate age
+    age_years = now.year - birthday.year
+    age_months = now.month - birthday.month
+    age_days = now.day - birthday.day
+
+    if(age_days < 0):
+        age_months -= 1
+
+        '''1. If the age_days is negative, it implies the month must be one less than the month number that is calculated and stored in age_months
+        2. "(now.month-1)%12 or 12" ensures that when the previous month is calculated, its value lie in the range [1, 12]
+        ''' 
+        previous_month = (now.month - 1) % 12 or 12
+
+        days_in_prev_month = (datetime.date(now.year, previous_month + 1, 1) - datetime.date(now.year, previous_month, 1)).days
+
+        age_days += days_in_prev_month
+
+    if (age_months < 0):
+        '''If age_months is negative, it implies the year must be one less than the year number that is calculated and store in age_years'''
+        age_years -= 1
+        age_months += 12
+
+    # Printing the current age of the user
+    print(f"Your birthday is {birthday.strftime('%d %B %Y')}\nYour current age is {age_years} years, {age_months} months and {age_days} days.")
+
+except ValueError:
+    print("Either the date or the format is invalid.")