Im stuck with the following:

Define a function isPrime(number) that takes in a number as argument and return True if the number is a prime number.

Hint: A number, x is a prime number if it is only divisible by 1 and x itself.
By definition, 1 is not a prime number.

``````Examples
>>> isPrime(97)
True
>>> isPrime(1)
False
>>> isPrime(-2)
False``````
``````# Hint: Step through the range between (2, number-1),
# and determine if the number is divisible using the modulus operator.
def isPrime(x):``````

p.s the topic this exercise is a part of is 'Conditionals'

## All 5 Replies

# and determine if the number is divisible using the modulus operator.

modulus returns the remainder of a number
ex.

``````>>> 10%4
2
>>> 10%2
0``````

if the answer is 0 then the number is perfectly divisible
this should give you a hint if the number is prime

``````def isprime(num):
for x in range(2, num):
if num % x == 0: return False
return True``````
commented: please let OP to do his part -3

sorry ihatehippies, your code doesn't work.

And thanks zeroliken, though i still dont get it, haha

``````def isprime(num):
if num < 2: return False
elif num == 2: return True
for x in xrange(2,num-1):
if not num % x: return False
return True``````

as mentioned above '%' returns the remainder

6%3 = 2 remainder 0, so it returns 0
6%4 = 2 remainder 2, so it returns 2

the function goes through the numbers between 2 and the number-1 and checks to see if any number is perfectly divisible.

``````def isprime(num):
if num < 2: return False
elif num == 2: return True
for x in xrange(2,num-1):
if not num % x: return False
return True``````

as mentioned above '%' returns the remainder

6%3 = 2 remainder 0, so it returns 0
6%4 = 2 remainder 2, so it returns 2

the function goes through the numbers between 2 and the number-1 and checks to see if any number is perfectly divisible.