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Author: somrajchowdhury

Course 1 - Python Programming Essentials/Project 1.py

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+"""
+Project for Week 4 of "Python Programming Essentials".
+Collection of functions to process dates.
+
+Be sure to read the project description page for further information
+about the expected behavior of the program.
+"""
+
+import datetime
+
+def days_in_month(year, month):
+    """
+    Inputs:
+      year  - an integer between datetime.MINYEAR and datetime.MAXYEAR
+              representing the year
+      month - an integer between 1 and 12 representing the month
+
+    Returns:
+      The number of days in the input month.
+    """
+    first_day_this_month = datetime.date(year, month, 1)
+    if month == 12:
+        first_day_next_month = datetime.date(year+1, (month%12)+1, 1)
+        num_days_this_month = first_day_next_month - first_day_this_month
+        return num_days_this_month.days
+    else:
+        first_day_next_month = datetime.date(year, month+1, 1)
+        num_days_this_month = first_day_next_month - first_day_this_month
+        return num_days_this_month.days
+
+def is_valid_date(year, month, day):
+    """
+    Inputs:
+      year  - an integer representing the year
+      month - an integer representing the month
+      day   - an integer representing the day
+
+    Returns:
+      True if year-month-day is a valid date and
+      False otherwise
+    """
+    if (datetime.MINYEAR <= year <= datetime.MAXYEAR) and (1 <= month <= 12) and (0 < day <= days_in_month(year, month)):
+        return True
+    else:
+        return False
+
+def days_between(year1, month1, day1, year2, month2, day2):
+    """
+    Inputs:
+      year1  - an integer representing the year of the first date
+      month1 - an integer representing the month of the first date
+      day1   - an integer representing the day of the first date
+      year2  - an integer representing the year of the second date
+      month2 - an integer representing the month of the second date
+      day2   - an integer representing the day of the second date
+
+    Returns:
+      The number of days from the first date to the second date.
+      Returns 0 if either date is invalid or the second date is
+      before the first date.
+    """
+    if (not(is_valid_date(year1, month1, day1)) or not(is_valid_date(year2, month2, day2))):
+        return 0
+    elif datetime.date(year2, month2, day2) < datetime.date(year1, month1, day1):
+        return 0
+    else:
+        days_between_dates = datetime.date(year2, month2, day2) - datetime.date(year1, month1, day1)
+        return days_between_dates.days
+
+def age_in_days(year, month, day):
+    """
+    Inputs:
+      year  - an integer representing the birthday year
+      month - an integer representing the birthday month
+      day   - an integer representing the birthday day
+
+    Returns:
+      The age of a person with the input birthday as of today.
+      Returns 0 if the input date is invalid or if the input
+      date is in the future.
+    """
+    todays_date = datetime.date.today()
+    if not(is_valid_date(year, month, day)):
+        return 0
+    elif year > todays_date.year:
+        return 0
+    else:
+        age_in_num_days = days_between(year, month, day, todays_date.year, todays_date.month, todays_date.day)
+        return age_in_num_days