Build a time calculator project

Python
1

Link to project:
https://www.freecodecamp.org/learn/scientific-computing-with-python/build-a-time-calculator-project/build-a-time-calculator-project

Hi guys, I am having trouble with my code for the time calculator project in the scientific computing with python course. So far, I have been calculating the addition of time and the number of days. I have ignored the days (monday, tuesday, etc) for now. There is a bug. If my input in the function is time in am, it works correctly, but when it is in pm, it is buggy and I am not sure why. I have gone through step by step what my code would do with the following input: ‘11:20 PM’, ‘24:30’ but my calculations/output is different to what python is doing. I would like a helping hand in what’s wrong with my code thanks!

code:


def add_time(start, duration, day_of_the_week=''):
    # Declaring variables
    days = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']
    current_day = day_of_the_week.lower().capitalize()   
    #print(current_day)
    am = 'AM'
    pm = 'PM'
    day_or_afternoon = '' # Where am or pm goes into
    adder = 0
    no_of_days = 0

    # Splitting duration into hours and minutes
    duration = duration.split(':')
    duration_hours = int(duration[0])
    duration_minutes = int(duration[1])
    #print(hours, minutes)

    # Checking how many 24 hours in duration_hours
    while duration_hours > 24:
        duration_hours -= 24
        no_of_days += 1
    #print(adder)
    #print(duration_hours)

    # Checking AM or PM
    start = start.split()
    #print(start)
    day_or_afternoon = start[1]
    #print(day_or_afternoon)

    # Splitting start into hours and minutes
    start = start[0].split(':')
    #print(start)
    start_hours = int(start[0])
    start_minutes = int(start[1])
    #print(start_hours, start_minutes) 

    # Adding hours
    start_hours += duration_hours
    while start_hours > 12:
        # am may switch to pm
        if day_or_afternoon == am:
            day_or_afternoon = pm
            start_hours -= 12
        # pm may switch to am and become a new day
        if day_or_afternoon == pm:
            day_or_afternoon = am
            start_hours -= 12
            no_of_days += 1

    # Adding minutes
    start_minutes += duration_minutes
    while start_minutes > 59:
        start_minutes -= 60
        start_hours += 1
        if start_hours > 12 and day_or_afternoon == am:
            day_or_afternoon = pm
            start_hours -= 12
        elif start_hours > 12 and day_or_afternoon == pm:
            day_or_afternoon = am
            start_hours -= 12
            no_of_days += 1

        # Note that if none of the if statements are met, then it must mean the current value of time and hours is already valid.
    
    if no_of_days != 0:
        formatted_days = f'({no_of_days} days later)' if no_of_days >=2 else f'(next day)'
    else:
        formatted_days = f''

    new_time = (f'{start_hours if start_hours != 0 else '00'}:{start_minutes if start_minutes != 0 else '00'} {day_or_afternoon} {formatted_days}').strip()
    
    return new_time

if __name__ == '__main__':
    print(add_time('11:20 PM', '24:30'))
    # Returns: 6:10 PM
2

don’t you see the syntax error in the terminal?
you are still inside a string, you can’t use single quotes inside a string defined with single quotes

3

But it works on visual studio code, hold on I will check it later and update you soon, going to sleep now.

4

Okay, here is my updated code with the bug removed. Could help me find out why it’s outputting -1.50am?


def add_time(start, duration, day_of_the_week=''):
    # Declaring variables
    days = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']
    current_day = day_of_the_week.lower().capitalize()   
    #print(current_day)
    am = 'AM'
    pm = 'PM'
    day_or_afternoon = '' # Where am or pm goes into
    adder = 0
    no_of_days = 0

    # Splitting duration into hours and minutes
    duration = duration.split(':')
    duration_hours = int(duration[0])
    duration_minutes = int(duration[1])
    #print(hours, minutes)

    # Checking how many 24 hours in duration_hours
    while duration_hours > 24:
        duration_hours -= 24
        no_of_days += 1
    #print(adder)
    #print(duration_hours)

    # Checking AM or PM
    start = start.split()
    #print(start)
    day_or_afternoon = start[1]
    #print(day_or_afternoon)

    # Splitting start into hours and minutes
    start = start[0].split(':')
    #print(start)
    start_hours = int(start[0])
    start_minutes = int(start[1])
    #print(start_hours, start_minutes) 

    # Adding hours
    start_hours += duration_hours
    while start_hours > 12:
        # am may switch to pm
        if day_or_afternoon == am:
            day_or_afternoon = pm
            start_hours -= 12
        # pm may switch to am and become a new day
        if day_or_afternoon == pm:
            day_or_afternoon = am
            start_hours -= 12
            no_of_days += 1

    # Adding minutes
    start_minutes += duration_minutes
    while start_minutes > 59:
        start_minutes -= 60
        start_hours += 1
        if start_hours > 12 and day_or_afternoon == am:
            day_or_afternoon = pm
            start_hours -= 12
        elif start_hours > 12 and day_or_afternoon == pm:
            day_or_afternoon = am
            start_hours -= 12
            no_of_days += 1

        # Note that if none of the if statements are met, then it must mean the current value of time and hours is already valid.
    
    if no_of_days != 0:
        formatted_days = f'({no_of_days} days later)' if no_of_days >=2 else f'(next day)'
    else:
        formatted_days = f''

    new_time = (f"{start_hours if start_hours != 0 else '00'}:{start_minutes if start_minutes != 0 else '00'} {day_or_afternoon} {formatted_days}").strip()
    
    return new_time

if __name__ == '__main__':
    print(add_time('11:20 PM', '24:30'))
    # Returns: 6:10 PM
5

Alright I noticed a bug. It is in this section of code:

# Adding hours
    start_hours += duration_hours
    while start_hours > 12:
        # am may switch to pm
        if day_or_afternoon == am:
            day_or_afternoon = pm
            start_hours -= 12
        # pm may switch to am and become a new day
        if day_or_afternoon == pm:
            day_or_afternoon = am
            start_hours -= 12
            no_of_days += 1
        #print(day_or_afternoon)

the day_or_afternoon variable does not change to PM and remains as AM throughout the iterations. How do I do the correct reassignment of the variable day_or_afternoon?

6

what are the possible values of day_or_afternoon?

where do the variables am or pm come from?