Prime/Perfect/Triangular Numbers & Functions (help) (homework)

[scrace89]

# This file contains python code that will determine whether a potivie range
# of integers entered by the user will contain odd or even numbers, prime or
# composite numbers, perfect/abundant/deficient numbers, square numbers, and
# triangular numbers.

def main():

    import math

    firstNum = 0
    secondNum = 0
    n = 0
    odd = 0
    prime = 0
    perfect = 0
    square = 0
    perfect = 0
    square = 0
    triangular = 0

    printGreeting()

    firstNum = input('Please enter an integer between 1 and 100000: ')
    secondNum = input('Please enter an interger greater than your pervious but not larger than 100000: ')

    for n in range(firstNum, secondNum + 1):
        isOdd(n)
        isPrime(n)
        checkForPerfect(n)
        isSquare(n)
        isTriangular(n)

    printTablLine(n, odd, prime, perfect, square, triangular)

main()
printGreeting():
    print 'This program classifies positive integers as Odd/Even,'
    print 'Prime/Composite, Perfect/Abundant/Deficient, Square,'
    print 'and Triangular.'
    print
    print 'You will now get to choose the range of positive intergers'
    print 'that you would like to see classified.'
    print

def printTableHeading():


def isOdd(n):
    if firstNum % 2 == 0:
        return False
    else:
        return True

def isPrime(n):
    if n == 2:
        return True
    for divisor in range(3, int(math.sqrt(n)), 2):
        if n % divisor == 0:
            return False
        return True

def checkForPerfect(n):

    sum = 0

    if n %  == 0:
        sum +=
    if sum == n:
        return 'Perfect'
    elif sum > n:
        return 'Abundant'
    else:
        return 'Abundant'
    else:
        return 'Deficient'


def sumDivisors(n):
# returns the sum of the divisors of n.

def isDivisor(a, b):
# a predicate function that returns True if b is a divisor of a, and False if not.

def isSquare(n):
# returns True if n is a perfect square, False if not.

def isTriangular(n):
# returns True if n is a triangular number, False if not.

def printTableLine(n, odd, prime, perfect, square, triangular):
# prints the information for one number on one line of the table.

This is my latest homework, could anyone help me find out the error in my isPrime() function. Also how do I set this up to print my return values, for example for isOdd() true = odd, so how would I get it to print Odd? I just need some direction, using functions and returns is confusing me.

Thanks for any input I'm a complete noob.

[woooee]

could anyone help me find out the error in my isPrime() function

You get a return on the first pass through the for() loop. A True if the first divide has a remainder, a False if the first divide has no remainder. You want the True after the for() loop, not within it.

def isPrime(n):
    if n == 2:
        return True
    for divisor in range(3, int(math.sqrt(n)), 2):
        if n % divisor == 0:
            return False

    ## did not return 'False' during the for() loop so it is prime
    return True

And this code will never print "Deficient". I'll let you figure out why.

def checkForPerfect(n):
 
    sum = 0
 
    if n %  == 0:
        sum +=
    if sum == n:
        return 'Perfect'
    elif sum > n:
        return 'Abundant'
    else:
        return 'Abundant'
    else:
        return 'Deficient'

[woooee]

so how would I get it to print Odd

def isOdd(n):
    if firstNum % 2 == 0:
        return False
    else:
        return True

for num in range( 97, 100 ):
    is_odd_returned = isOdd(num)
    print num, "is",
    if is_odd_returned == True:  ## or just if is_odd_returned:
        print "Odd"
    else:    ## "False' returned
        print "Not odd"

[scrace89]

awesome, thank you. Ya i didn't noticed i think i copied from an area i alrdy copied before i pasted. I'll come back once I work on it more when I get stuck.

thanks again

[pysup]

I think 2 more lines need to be added for isPrime function

def isPrime(n):
    if n == 2:
        return True

    if n%2 == 0 :
        return False

    for divisor in range(3, int(math.sqrt(n)), 2):
        if n % divisor == 0:
            return False

    ## did not return 'False' during the for() loop so it is prime
    return True

[scrace89]

def isSquare(n):
    import math    
        if math.sqrt(n) == :
            print 'True'
        else:
            print 'False'

This is what I have so far, I need it to return True if its a perfect square, like 1, 4, 9 ect. and false if not. After finding the root how can I compare it so if it has a decimal return false. i tried

if math.sqrt(n) == int:
                print 'True'

but no matter what it prints true.

[scrace89]

also for my function isTriangular

def isTriangular(n):

    x = (math.sqrt(8 * n + 1) - 1) / 2
    if x - int(x) > 0:
        return False
    return True

returns false if not and true if it is. Can anyone explain the

x = (math.sqrt(8 * n + 1) - 1) / 2

triangular numbers have sums of consecutive ints like 1+2 = 3, 1+2+3=6 1+2+3+4 = 10 and ect.

[Gribouillis]

Can anyone explain the

x = (math.sqrt(8 * n + 1) - 1) / 2

triangular numbers have sums of consecutive ints like 1+2 = 3, 1+2+3=6 1+2+3+4 = 10 and ect.

A number n is triangular if it has the form n = k(k+1)/2. For example 1+2 = 2*3/2, 1+2+3=3*4/2, 1+2+3+4=4*5/2. If you compute 8n+1, you have 8n+1 = 4k(k+1)+1 = 4 k^2 + 4k + 1 = (2k+1)^2 , so this gives k = (sqrt(8n+1) -1)/2 .