String Splits

[m.zod]

Hey guys, I'm a new student to Python 3, and I'm having some issues with an assignment, so I'd appreciate the help.
What I'm doing in the assignment is taking a user-inputted string, splitting it, and printing it out in a triangle (if it's even, inverted triangle if it's odd, but I have that part working great)
So here's where I have a problem.

if len( myString ) % 2 == 0:
    numA = ( len( myString ) / 2 )
    numB = ( numA + 1 )
    halfA = myString [ : ( numA ) ]
    halfB = myString [ ( numB ) : ]

So, the string is identified as being eve, and I'm making the attempt to use a string-split to only print half the string at a time.

When this runs, I receive an error that states:

Error:
TypeError: slice indices must be integers or None or have an __index__ method

We haven't learned about any __index__ method, and my text book, as well as online resources, aren't giving me any clues as to what I'm doing wrong.
If I NEED to use an integer in my string-split, I don't know how to do it gracefully. The only thing I can think of is to have if statements for each possible even-numbered string.

Thanks for the help guys, I appreciate it!

[wavic]

Put below numA = ( len( myString ) / 2 ) print(type(numA)).

It seams that it is float and that can't be used as an index or into index operations like slicing.

[nilamo]

Yep, a simple

numA = int( len(mystring)/2 )

should help.

[wavic]

It's the python3 way. Division operation returns float.

victor@jerry:~$ python3
Python 3.5.2 (default, Sep 10 2016, 08:21:44) 
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> a = 100 / 2
>>> type(a)
<class 'float'>
>>>