🔒 MOOC exercise

[static pike]

Kinda blank on what to do next. Also I've been regularly posting for help for the exercises I'm doing is that bad? I mean the people that help me dont directly give me the answer they guide me and I end up reaching the solution myself is this a bad thing or still learning. I still feel satisfied when i reach the solution but it sucks when I start the exercise and my mind goes blank

Anyways the topic we just learnt is nested while loops (ive been on the same topic for a couple days since i didnt touch the mooc) so im expecting to use it within this exercise

what we've already done is check if the number is less than or equal to 0 completely break the program, what we need to program now is the factorial function basically

[errant pulsar]

@static pike

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[static pike]

I jus noticed lol but the first line should be
a while loop

[lethal hemlock]

asking for help definitely isn't a bad thing

what you'd want to do next is compute the factorial of the number that the user has inputted. You can do this by iterating through all of the numbers between 1 and num and multiplying them all together

[static pike]

iterating through the numbers would be so much easier with a for loop but theyve only taught me a while loop in this course so far so I dont think they want me to use a for loop

should I just use a for loop anyways (ive learnt it before)

[lethal hemlock]

if you wanted to use a while loop you could decrement num by 1 until it reaches 0

you'd sort of be doing it backwards, but since the order doesn't matter when multiplying integers it won't make any difference

[static pike]

the iteration part, how would i write that out

while num > 0: 
  # write the factorial logic
  num -= 1 # loop carries on until reaches 0

[lethal hemlock]

yes, you could do that

[static pike]

im just tryna think of how to actually write the factorial logic but so clueless sry lol 💀

example of how it wants me to print
Please type in a number: 3
The factorial of the number 3 is 6

should I write the print f string there now or later

[lethal hemlock]

that's okay! If I was writing it then I'd probably initialize a variable as 1 (because 1 is the multiplicative identity) and then inside the while loop I'd multiply it by num. So, for example, if num was 3, then this would happen:
result = 1, num = 3
first iteration: result = 3, num = 2
second iteration: result = 6, num = 1
final iteration: result = 6, num = 0

[static pike]

ohh so you'd keep on adding it to the result each time it loops

[lethal hemlock]

it is more like we're multiplying result by it each time it loops

[static pike]

num = int(input("Please type in a number: "))

while num <= 0:
    break

result = 1

while num > 0:
    result *= num
    num -= 1

print(f'The factorial of the number {num} is {result}')
print("Thanks and bye!")

it prints out
Please type in a number: 3
The factorial of the number 0 is 6
Thanks and bye!

it prints out num as 0 bcs its 0 after the while loop, I probably put the print at the wrong location

[lethal hemlock]

ah that's because we've modified num in the while loop

you could store the initial value in another variable so you can print it out at the end

[static pike]

okay now one thing i didnt realise until now lol is that our program ends once it gets the factorial of one number

but its meant to keep going until user inputs something less than or equal to 0

so we probably need a loop to keep asking for user input

[lethal hemlock]

yeah, you would have to wrap the whole thing in a while loop

[static pike]

the entire program?

[static pike]

but what sort of condition would we set for this loop

[lethal hemlock]

well, we want all of the steps to happen for each number

[lethal hemlock]

you could do something like this```py
while True:
# get user input...
# break if num is not positive
# calculate factorial

or...```python
num = # get user input
while num <= 0:
# calculate factorial here
# get user input again

[static pike]

but

[static pike]

wouldnt this be wrong? we dont want to calculate anything if the number is less than or equal to 0

did you mean while num >= 0:

num = int(input("Please type in a number: "))

temp = num

while num <= 0:
    break

result = 1

while num > 0:
    result *= num
    num -= 1

print(f'The factorial of the number {temp} is {result}')
print("Thanks and bye!")

(just leaving my current code here, this only works for one input)

[static pike]

I mightve written this wrong but when i did this but if the user inputted lets say 3 it would do it and ask to input again but if i inputted 0 it would carry on

[lethal hemlock]

ah you're right, it should be num > 0

[static pike]

num = int(input("Please type in a number: "))
temp = num

result = 1

while num > 0:
    result *= num
    num = int(input("Please type in a number: "))
    num -= 1

print(f'The factorial of the number {temp} is {result}')
print("Thanks and bye!")

uhh

small problem

[lethal hemlock]

so you should really have two loops here

one which loops every time the user wants to calculate the factorial of a new number and an inner one which actually multiplies the numbers together

[static pike]

so something like this?

while num > 0:
    num = int(input("Please type in a number: "))
    while True:
        result *= num
        num -=1

or otherway round

[lethal hemlock]

yeah it would be structured like that

[static pike]

where would you put the print statement

[lethal hemlock]

after the inner loop

because after that you will have computed the factorial of the number

[static pike]

program infinitely loops after this

maybe while True first

[lethal hemlock]

yeah, I think the while True version is a little easier to get your head around

[static pike]

do we still need a nested loop with the while true method

[lethal hemlock]

plus, it means that you can use your code from earlier (#1416463055084326993 message) without changing too much

[lethal hemlock]

yes

[static pike]

ok cool now my program works with the factorial and prints properly but it doesnt end when you input 9

0*

done

all i had to do was add a if statement to break if its <= 0

while True:
    num = int(input("Please type in a number: "))
    temp = num

    if num <= 0:
        break

    result = 1

    while num > 0:
        result *= num
        num -= 1
    print(f'The factorial of the number {temp} is {result}')

print("Thanks and bye!")

ty! (its time to get stuck on the next exercise )

[lethal hemlock]

nice!

[static pike]

!close

[errant pulsar]

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