Lab 4

"""
Date Handling
"""
import datetime

def name_of_weekday(date):
    """What is the name of the weekday?

    No work needed.  But, notice that:
    1. date.weekday() returns an index 0 through 6.
    2. we use that index to get a name.
    """
    weekday_names = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
    return weekday_names[date.weekday()]

#--------------------------------------------------------------
# IMPLEMENT THE FUNCTIONS BELOW THIS LINE

def text_to_ymd(text):
    """
    Convert text into a year, month, day
      ISO: YYYY-MM-DD
    """
    # 1. split the text on "-":
    #     year, month, day = text.split("-")
    # 2. Convert all three values into ints
    # 3. Return the three values: year, month, day

    year, month, day = text.split("-")

    # REPLACE THIS LINE:
    return int(year), int(month), int(day)

def new_years_day():
    """
    What day of the week was this year's January 1st?
    """

    # 1. Get today's date:
    #      today = datetime.date.today()
    # 2. get the year: today.year
    # 3. Make and return new date object:
    #      return datetime.date(y, m, d) (pick y, m, d appropriately)

    today = datetime.date.today()
    year = today.year

    # REPLACE THIS LINE:
    return datetime.date(year, 1, 1)

def n_weeks_after_newyears(n_weeks):
    """What day was n_weeks weeks after new year's day?
    """

    # 1. Call new_years_day() to get the first date of this year.
    # 2. Call datetime.timedelta( X ), which is an interval.
    #    X is the number of days. (remember 7 days per week).
    # 3. Add that to the first date, and return

    first_date = new_years_day()
    week = datetime.timedelta(n_weeks * 7)
    result = first_date + week

    # REPLACE THIS LINE:
    return result

def first_thursday(month):
    """What was the first Thursday of the given month (this year)?
    """

    # 1. Get today, and get today.year to get this year.
    # 2. make a date = datetime.date(year, month, 1) for first day of month.
    # 3. Loop:
    #      while True:
    # 4. inside loop, check if date.weekday() == 3
    #      if so, it's Thursday.  break.
    # 5. otherwise, add one day:
    #      date += datetime.timedelta(1)
    # when done, return date

    today = datetime.date.today()
    year = today.year
    date = datetime.date(year, month, 1)
    while True:
        if date.weekday() == 3:
            break
        else:
            date += datetime.timedelta(1)


    # REPLACE THIS LINE:
    return date

def thanksgiving_thursday():
    """What day is the third Friday of November, this year?
    """
    # 1. Get first Thursday of November (call first_thursday(11))
    # 2. add 14 days to it, and return

    x = first_thursday(11)
    x += datetime.timedelta(14)

    # REPLACE THIS LINE:
    return x

def days_until_thanksgiving():
    """How many days from today until this year's thanksgiving?
    """
    # 1. Call thanksgiving Thursday
    # 2. Subtract today's date:
    #  delta = thanksgiving_thursday() - datetime.date.today()
    # 3. return delta.days

    thanksgiving_thursday()
    delta = thanksgiving_thursday() - datetime.date.today()

    return delta.days

def election_day(year):
    """When is election day, on the given year?
    It's the first Tuesday AFTER the first Monday of November.
    """
    # You can do it!
    # FIND THE FIRST MONDAY OF NOV
    # THEN ADD ONE DAY

    #today = datetime.date.today()
    #year = today.year
    date = datetime.date(year, 11, 1) #2016 Nov 1st
    while True:
        if date.weekday() == 3: #IF IT FINDS THURSDAY
            date += datetime.timedelta(3) #ADD 3 DAYS WHIC IS MONDAY
            break
        else:
            date += datetime.timedelta(1)

    # REPLACE THIS LINE:
    return date

def is_leap_year(year):
    """Is the given year a leap year?
    """
    if year % 400 == 0:
        return True
    if year % 100 == 0:
        return False
    if year % 4 == 0:
        return True
    else:
        return False
    """
    Rules (proleptic Gregorian calendar):
    1. If the year is not divisible by 4, it's NOT a leap year.
       return False
    2. if the year IS divisible by 400, it's NOT a leap year.
    3. otherwise, it's a leap year.
    """

    # REPLACE THIS LINE:
    return None

# IMPLEMENT THE FUNCTIONS ABOVE THIS LINE
#-------------------------------------------------------------

def main():
    for text_date in ["2008-09-01", "2015-08-23"]:
        year, month, day = text_to_ymd(text_date)
        date = datetime.date(year, month, day)
        print("{:<22} : {}".format(text_date, date))
    print("New Year's Day          ", new_years_day())
    print("New Year's was a        ", name_of_weekday(new_years_day()))
    print("10 weeks later is a     ",
          name_of_weekday(n_weeks_after_newyears(10)))
    print("First Thursday of Sept: ", first_thursday(9))
    print("Thanksgiving:           ", thanksgiving_thursday())
    print("Days until thanksgiving:", days_until_thanksgiving())
    election = election_day(2016)
    print("Election day 2016:      ", election)
    print("Election day was a      ", name_of_weekday(election))

    for decade in range(1980, 2020, 10):
        for year in range(decade, decade + 10):
            print("{:>4} ".format(year), end = "")
        print()
        for year in range(decade, decade + 10):
            if is_leap_year(year):
                print("{:>4} ".format("Leap"), end = "")
            else:
                print("{:>4} ".format(""), end = "")
        print()

if __name__ == '__main__':
    main()