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# odd_even.py

code passes challenge. when i run the code in workspaces, no errors - and no output. what am i missing to run and see output?

thanks much.

```def even_odd(num):
# If % 2 is 0, the number is even.
# Since 0 is falsey, we have to invert it with not.
return not num % 2

start = 5
while start == True:
random_number =  random.randint(1, 99)
number = even_odd(random_number)
if number == True:
print(" {} is even".format(random_number))
else:
print(" {} is odd".format(random_number))
start -=1
```

MOD

The `while` loop will never run because

```start == True
```

is never `True`. While `start can be "truthy" it wii never be equal to`True`. Simply use the "truthiness" is`start`:

```while start:
```

This extends to using `if number:` instead as well.

Thanks Chris! Another logic question... I understand that if num % 2 is 0, then we've got an even num. Trying to understand the use of 'not'. Is the below saying 'return not 0' -- meaning return true? And if so, then how does even_odd function ever indicate num is an even number, which would be returning a 0... ?

```return not num % 2
```

It has to do with context.

```# True and False can be cast as integers
>>> int(True)
1
>>> int(False)
0
# and can be compared with integers
>>> 1 == True
True
>>> 0 == False
True
# but are Not integers
>>> 0 is False
False
>>>
# they are Boolean
>>> type(False)
<class 'bool'>

# modulo % returns an int
>>> 5 % 2
1
# the 'not' says "return the opposite of the truthiness of the expression"
>>> not 5 % 2
False
>>> not 1
False
```

So because the `not` casts its output as Boolean, `even_odd` returns a Boolean.

Hope that makes sense.