Integers

You may already know a little about how computers perform calculations on numbers. Perhaps you've heard of the binary system, and know that it's the system computers use for storing numbers, and that they can perform any operation upon them.

We won't explore the intricacies of positional numeral systems here, but we'll say that the numbers handled by modern computers are of two types:

• integers, that is, those which are devoid of the fractional part;
• and floating-point numbers (or simply floats), that contain (or are able to contain) the fractional part.

This definition is not entirely accurate, but quite sufficient for now. The distinction is very important, and the boundary between these two types of numbers is very strict. Both of these kinds of numbers differ significantly in how they're stored in a computer memory and in the range of acceptable values.

The characteristic of the numeric value which determines its kind, range, and application, is called the type.

If you encode a literal and place it inside Python code, the form of the literal determines the representation (type) Python will use to store it in the memory.

For now, let's leave the floating-point numbers aside (we'll come back to them soon) and consider the question of how Python recognizes integers.