To do it the way you're trying to do it, use this:
Notice I put brackets around num since you have to add a list to a list when using the + operator. Other methods would be to use mylist.append(num) or mylist.insert(index, num) . I also changed your x = x + y statements to x += y , which is identical.

HTH

Some corrections:

So what you basically want is to fill the list with a sequence of numbers? Why?

I'm not getting it to print anything! I'll post the exact code I am working with... I'm trying to convert from deci to binary and print the binary number using the list method.

remain = 0
quo = 1
mynum = []

deci = int(raw_input("Please enter a decimal integer:"))

while quo != 0:

quo = deci / 2

remain = deci / 2

mynum.append(remain)

print(mylist)

for item in mynum:
print item

"I'm not getting it to print anything! I'll post the exact code I am working with... I'm trying to convert from deci to binary and print the binary number using the list method."
...
so you're trying to convert a number from decimal to binary??
here's a hint how to do that

number = 14
14 / 2 = 7, remainder = 0
7 / 2 = 3, remainder = 1
3 / 2 = 1, remainder = 1
1 / 2 = 0, remainder = 1

therefore 14 in binary is 1110
you can use l.insert( 0, num ) to deal with the reverse order, where l is a list

hope that helps!