The issue arises because the string you are trying to print is not a string, rather a float value. Item1, item2 and item3 are strong values (if you type some alphabets in it and not just numbers), but itemonecost, itemtwocost, and itemthreecost are explicitly type casted to float. In line 22, 23, and 24 you’re trying to print a float, by adding it with the string. One cannot add numbers to string. Rather you can type cast the itemcost to string while printing.
Add str(itemonecost) instead of itemonecost in print statement. Do this for other float variables too.
However do note that there are multiple ways to correct this issue, and I’ve just pointed one out.
Optima battery because it is stronger than a factory battery
I've never seen that third syntax. If it's legit, it probably does the same as I and II, which are the same.
<span>a representation in which each item corresponds to one or more bits of information, especially the information used to control the display of a computer screen.
</span><span>represent (an item) as a bitmap.
</span>
