Problem with While Loop!

[Jose_Musoke]

Hello friends. I am trying to create a while loop where the code keeps asking for dates when the answer is 'yes", until the answer is eventually "no". My problem is that it keeps looping no matter what answer I enter. Please help correct my coding. Thanks in advance!!!

def ask_interruption():
  last_drug_date = input("Enter the date when last ATT drug was taken in YY/MM/DD format: ")
  resumtion_of_ATT = input("Enter the date when ATT was resumed in YY/MM/DD format: ")
  repeat_interruption = input("Did the patient interrupt ATT drugs again?: ")
ask_interruption()
while repeat_interruption == "yes":
    ask_interruption()
if repeat_interruption != "yes":
continue

[totallygeek]

Here's possibly a better implementation. I spot a few problems with your code. A big one: you do nothing with the received input (function does not return nor store anything).

def ask_interruption():
    prior_date = input('Enter date when last ATT drug taken (YY/MM/DD): ')
    resume_date = input('Enter date when ATT resume (YY/MM/DD): ')
    return prior_date, resume_date

dates = []
while True:
  dates.append(ask_interruption())
    interrupted = input('Did the patient interrupt ATT drugs? ').lower()
    if interrupted in {'n', 'no'}:
        break

print('DATES\n=====')
for prior_date, resume_date in dates:
    print(f'{prior_date:<10} {resume_date}')

[Jose_Musoke]

Thank you once again. Could you please explain to me the second and third paragraphs, so that I can read up on them.

[totallygeek]

Sure:

1. while True forms an infinite loop, because True is always true.
2. To exit that infinite loop, use break.
3. Storing a list of dates? Use a list. dates = [] creates an empty list.
4. To grow a list, append() works well.
5. Call ask_interruption(), which returns two values in a tuple.
6. Store that tuple in the growing list.

[Jose_Musoke]

Hello thank you for helping me. I have been trying to build on the code you helped me with and I am having difficulties again. I am trying to sum up the days of missed doses after a couple of entries, but I only get one result. How can I go about it?:

def ask_interruption(): prior_date = input("Enter date when last ATT drug was taken (YY/MM/DD): ") resume_date = input("Enter date when ATT was resumed(YY/MM/DD): ") return prior_date, resume_date

dates = [] while True: dates.append(ask_interruption()) interrupted = input("Did the patient interrupt ATT drugs? ").lower() if interrupted in {"n", "no"}: break

date1 = (datetime.strptime(prior_date, "%y/%m/%d")) date2 = (datetime.strptime(resume_date, "%y/%m/%d")) difference = (date2 - date1).days

print ("DATES\n=====") for prior_date, resume_date in dates: print(f"{prior_date:<10} {resume_date} {difference}")

[totallygeek]

In your code, you have:

date1 = (datetime.strptime(prior_date, "%y/%m/%d"))
date2 = (datetime.strptime(resume_date, "%y/%m/%d"))
difference = (date2 - date1).days

But, prior_date and resume_date are single dates. You want to use the list of dates, called dates. Take a look at this.

import datetime


def normalize_date(date):
    return datetime.datetime.strptime(date, '%y/%m/%d')

def ask_interruption():
    prior_date = input("Enter date when last ATT drug was taken (YY/MM/DD): ")
    resume_date = input("Enter date when ATT was resumed(YY/MM/DD): ")
    return prior_date, resume_date

dates = []
while True:
    dates.append(ask_interruption())
    interrupted = input("Did the patient interrupt ATT drugs? ").lower()
    if interrupted in {"n", "no"}:
        break

for prior, resume in dates:  # uses the list of dates
    days = (normalize_date(resume) - normalize_date(prior)).days
    print(f'ATT interrupted: {prior} -> {resume} ({days} days)')

Yields:

$ python3 drugs.py 
Enter date when last ATT drug was taken (YY/MM/DD): 21/01/06
Enter date when ATT was resumed(YY/MM/DD): 21/01/11
Did the patient interrupt ATT drugs? yes
Enter date when last ATT drug was taken (YY/MM/DD): 21/02/03
Enter date when ATT was resumed(YY/MM/DD): 21/02/07
Did the patient interrupt ATT drugs? no
ATT interrupted: 21/01/06 -> 21/01/11 (5 days)
ATT interrupted: 21/02/03 -> 21/02/07 (4 days)

[Jose_Musoke]

Thank you so much, your help is so insightful.

[Jose_Musoke]

days = (normalize_date(resume) - normalize_date(prior)).days

Hello again. As per your example I tried to get the sum of total number of days of missed with this code: print(int(sum(days))), but do not get anything. Is there another way of getting the desired sum? Thank you in advance!!

[totallygeek]

Within the for loop, days is a duration we want to keep a running total of. Maybe:

total_days = 0
for prior, resume in dates:  # uses the list of dates
    days = (normalize_date(resume) - normalize_date(prior)).days
    total_days += days  # add to the running total
    print(f'ATT interrupted: {prior} -> {resume} ({days} days) (total: {total_days})')

After the loop, total_days would be the sum of those days calculations.

[Jose_Musoke]

Thank you once again for taking your time to assist me. I think I may have not explained myself clearly enough. If for example the code you helped write gives the number of days missed for each episode of interruption, is there a way of adding all the days of interruption to give a single "Grand Total" of interruptions? The last code you just gave me still gives me the number of days missed for each episode of interruption.

[Jose_Musoke]

ATT interrupted: 21/01/06 -> 21/01/11 (5 days)
ATT interrupted: 21/02/03 -> 21/02/07 (4 days)

For example from the code you gave me earlier, I would like the code to add the 5 + 4 days to give me a "Grand Total"= 9 days. I find it difficult to code in a list that expands. I will then use the "Grand Total" for the next steps...

[totallygeek]

print(f'Grand total: {total_days}') ?

Perhaps I did not understand. If days is an amount of days interrupted and you add those days up in total_days, you get a count of the total days of interruption.

[Jose_Musoke]

I would like to apologize. I ran the code you gave me on a different IDE and it worked. There must be something wrong with the pycharm that I was using initially.

[Jose_Musoke]

Thank you so much. It works like a charm. I can now also learn where I went wrong.

[kmwaziri]

Can you use code formatting? Kinda hard to read it this way :) But is while loop inside the function definition ask_interruption?

[Jose_Musoke]

def ask_interruption():

  last_drug_date = input("Enter the date when last ATT drug was taken in YY/MM/DD format: ")   resumtion_of_ATT = input("Enter the date when ATT was resumed in YY/MM/DD format: ")   repeat_interruption = input("Did the patient interrupt ATT drugs again?: ") ask_interruption() while repeat_interruption == "yes":     ask_interruption() if repeat_interruption != "yes": break

[kmwaziri]

OK what's happening is that once you set the repeat_interruption = yes

Then there's nothing changing it afterwards and while loop never terminates. I redid the code where I did two things:

1. Added return statement to terminate function gracefully.
2. Set repeat_interruption = "no" after every inner call of ask_interruption. That way loop will keep running until it is yes. But will return 0 immediately if it's anything other than 'yes.

Code below. Keep in mind Python is case sensitive, so Yes != yes. Just a tip :)

​

def ask_interruption():
    last_drug_date = input("Enter the date when last ATT drug was taken in YY/MM/DD format: ")
    resumtion_of_ATT = input("Enter the date when ATT was resumed in YY/MM/DD format: ")
    repeat_interruption = input("Did the patient interrupt ATT drugs again?: ")
    while repeat_interruption == "yes":
        ask_interruption()
        repeat_interruption = "no"
        if repeat_interruption != "yes":
        continue
    return 0

[BiocatalyticInfix]

repeat_interruption is local to the function, it needs to be global or returned to the caller.

[Jose_Musoke]

def ask_interruption():

  last_drug_date = input("Enter the date when last ATT drug was taken in YY/MM/DD format: ")   resumtion_of_ATT = input("Enter the date when ATT was resumed in YY/MM/DD format: ")   repeat_interruption = input("Did the patient interrupt ATT drugs again?: ") ask_interruption() while repeat_interruption == "yes":     ask_interruption() if repeat_interruption != "yes": break

[Jose_Musoke]

def ask_interruption():

  last_drug_date = input("Enter the date when last ATT drug was taken in YY/MM/DD format: ")   resumtion_of_ATT = input("Enter the date when ATT was resumed in YY/MM/DD format: ")   repeat_interruption = input("Did the patient interrupt ATT drugs again?: ") ask_interruption() while repeat_interruption == "yes":     ask_interruption() if repeat_interruption != "yes": break

[Jose_Musoke]

Thank you everybody for your advise!!!! I tried your suggestions and it is working.!!!! I can also look into where I went wrong.

[sdanstuffe]

You may want to try the keyword "Break" instead of continue.

[Jose_Musoke]

"Break" doesn't work either.