AI 2022-10-12

"""
Problem: write a Python script that keeps
asking non-negative integers to a user.
To stop entering numbers, the user must
enter "-1".
While the user does NOT enter -1, we'll
keep track of the following values:
- minimum value
- maximum value
- sum of all values
- average of values
"""

# variables
# nMin = nMax = nSum = nAverage = 0 # cascade assignments
nMin = None # keeps track of the min value
nMax = None #
nSum = 0 # neutral
nAverage = None
nUserNum = None # the number the user enters

# constant
STOP_NUMBER = -1 # the number that must be entered to stop the program

SOME_QUESTION_ENG = \
    "Please enter a non-negative integer (-1 to stop):"

iHowManyNumbersTheUserHasEntered = 0
"""
strAnswer:str = input(SOME_QUESTION_ENG)
nUserNum = int(strAnswer) # cast str->int
"""

def askTheUserForNumber(
    pTheQuestion=SOME_QUESTION_ENG # default value
):
    try:
        strAnswer = input(pTheQuestion)
        iAnswer = int(strAnswer) # RTE for banana
        return iAnswer
    except Exception as e:
        strMsg = "Please, write an integer!"
        print (strMsg)
        return None
    # try-except
# def askTheUserForNumber

# := in python 3.8
while ((nUserNum:=askTheUserForNumber())!=-1):
    if (nUserNum!=None):
        iHowManyNumbersTheUserHasEntered+=1

        # keep track of nMax
        if(nMax==None):
            nMax=nUserNum
        # if
        else:
            if(nUserNum>nMax):
                nMax = nUserNum
            # if
        # else

        # keep track of nMin
        if(nMin==None): # first number
            nMin=nUserNum
        else:
            if(nUserNum<nMin):
                nMin = nUserNum
            # if
        # else

        # nSum = nSum + nUserNum
        # using the cumulative-add operator
        nSum += nUserNum # equivalent to the above
        # nSum -= nUserNum # nSum = nSum - nUserNum
        # nSum *= nUserNum # nSum = nSum * nUserNum
        # nSum /= nUserNum # nSum = nSum / nUserNum

        nAverage = nSum / iHowManyNumbersTheUserHasEntered

        # give feedback of what is happening
        strMsg:str=f"Current user number: {nUserNum}\n"
        strMsg += f"How many numbers were entered yet:" \
                  f" {iHowManyNumbersTheUserHasEntered}\n"
        strMsg+=f"Current max: {nMax}\n"
        strMsg+=f"Current min: {nMin}\n"
        strMsg += f"Current sum: {nSum}\n"
        strMsg += f"Current average: {nAverage}\n"
        print(strMsg)
    # if the user entered an integer
# while