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Python Integer Data Type (int)

What is an Integer?​

Integers are numbers without any decimal point.

# Examples 
a = 10
b = 0
c = -25

All of these are integers because:

  • They do not contain fractional values
  • They represent whole numbers
  • Integers are also called:
    • Whole numbers
    • Integral values

Integer Type in Python​

Let us verify the type of an integer:

a = 10
print(type(a)) # <class 'int'>

This confirms that Python treats 10 as an object of type int.

a = 10
b = 123456789012345678901234567890
  • In Python, no need to worry about size.
  • Python automatically handles large numbers.

Python does not require separate data types like long in Python 3.

Ways to Represent Integers in Python​

Python allows integers to be represented in four different number systems:

  • Decimal
  • Binary
  • Octal
  • Hexadecimal

1. Decimal Form (Base 10)​

  • Default number system
  • Uses digits: 0–9
a = 123
b = 987

If no prefix is used, Python assumes the number is decimal.

2. Binary Form (Base 2)​

Uses only 0 and 1.

a = 0b1111
print(a) # 15

Binary numbers must start with 0b or 0B.

3. Octal Form (Base 8)​

Uses digits: 0–7

a = 0o123
print(a) # 83

8 and 9 are not allowed in octal. Octal numbers must start with 0o or 0O.

4. Hexadecimal Form (Base 16)​

Uses digits:

  • 0–9
  • A–F (or a–f)
a = 0x10
print(a) # 16

Hexadecimal numbers must start with 0x or 0X.

Important Behavior of Python​

Always Outputs in Decimal​

No matter how you define the number:

a = 0b1010
print(a) # 10

Python always converts numbers to decimal when printing.

Base Conversion​

If you want output in other formats:

  • bin() → Binary
  • oct() → Octal
  • hex() → Hexadecimal