CODEWITHSUNDEEP
python
Thurgood Westlake
Thurgood Westlake

Reputation: 3

Doubling amount per day, need to convert number of pennies to dollars + cents

This program starts with 1 cent and doubles each day. However, I'm stuck on trying to find a way to convert the number of pennies into a dollar and cent amount. For example, converting 1020 pennies to $10.20.

I'm also attempting to make it so if user input is not a positive number, the user will be continously prompted until they enter a positive number. This isn't working, however.

I also feel I've messed up by using range, as I want to enter a set number of days, say 16 days, and when I enter 16, I receive the days 1-17, as range should be doing, and I'm not sure how to go about fixing that.

b = int(input("Input number of days "))

if b > 0:
    print(b)
else:
    b = int(input("Days must be positive "))


print("Day 1:","1")
days = 1
aIncrement = 2 
penny = 1



for i in range(b):
    pAmount = int(penny*2) 
    addAmount = int(2**aIncrement -1) 
    aIncrement +=1
    days +=1
    penny *= 2 
    print("Day " + str(days) + ":",pAmount)

Upvotes: 1

Views: 1847

Answers (2)

E. Ducateme
E. Ducateme

Reputation: 4248

Your question has multiple parts, which is not ideal for stackoverflow, but I will try to hit them all.

Fixing the numeric values to show dollars and cents.

As noted in comments to other answers, division can often run into snags due to floating point notation. But in this case, since all we really care about is the number of times 100 will go into the penny count and the remainder, we can probably safely get away with using divmod() which is included with Python and calculates the number of times a number is divisible in another number and the remainder in whole numbers.

For clarity, divmod() returns a tuple and in the sample below, I unpack the two values stored in the tuple and assign each individual value to one of two variables: dollars and cents.

    dollars, cents = divmod(pAmount, 100)           # unpack values (ints)
                                                    # from divmod() function
    output = '$' + str(dollars) + '.' + str(cents)  # create a string from
                                                    # each int

Fixing the range issue

The range() function produces a number and you can set it to start and end where you want, keeping in mind that the ending number must be set at one value higher than you want to go to... i.e. to get the numbers from one to ten, you must use a range of 1 to 11. In your code, you use i as a placeholder and you separately use days to keep track of the value of the current day. Since your user will tell you that they want b days, you would need to increment that value immediately. I suggest combining these to simplify things and potentially using slightly more self-documenting variable names. An additional note since this starts off on day one, we can remove some of the setup code that we were using to manually process day one before the loop started (more on that in a later section).

days = int(input("Input number of days "))   

for day in range(1, days + 1):
    # anywhere in your code, you can now refer to day
    # and it will be able to tell you the current day

Continuous input

If we ask the user for an initial input, they can put in:

  • a negative number
  • a zero
  • a positive number

So our while loop should check for any condition that is not positive (i.e. days <= 0). If the first request is a positive number, then the while loop is effectively skipped entirely and the script continues, otherwise it keeps asking for additional inputs. Notice... I edited the string in the second input() function to show the user both the problem and to tell them what to do next.

days = int(input("Input number of days "))

while days <= 0:
    days = int(input("Days must be positive, input positive number of days: "))

Putting all this together, the code might look something like this:

I put the items above together AND cleaned up a few additional things.

days = int(input("Input number of days "))

while days <= 0:
    days = int(input("Days must be positive, input number of days: "))

# aIncrement = 2        # this line not needed
penny = 1

for day in range(1, days + 1):
    pAmount = int(penny)                      # this line was cleaned up
                                              # because we don't need to manually
                                              # handle day one
    dollars, cents = divmod(pAmount, 100)
    output = '$' + str(dollars) + '.' + str(cents)
    # addAmount = int(2**aIncrement -1)    # this line not needed
    # aIncrement +=1                       # this line not needed
    penny *= 2 
    print("Day " + str(day) + ":", output)

Upvotes: 1

wjh18
wjh18

Reputation: 820

For the continuous prompting, you can use a while loop.

while True:
    user_input = int(input("Enter the number"))
    if user_input > 0:
        break
    else:
        continue

Or alternatively:

user_input = int(input("Enter the number"))

while user_input <= 0:
    user_input = int(input("Enter the number"))

For the range issue, you can add -1 to the parameter you're passing range.

for i in range(b - 1):

Upvotes: 0

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