Built-in Types

Booleans

bool: A boolean value of either True or False. Logical operations like and, or, not can be performed on booleans.

x or y    # if x is False then y otherwise x 
x and y   # if x is False then x otherwise y
not x     # if x is True then False, otherwise True

In Python 2.x and in Python 3.x, a boolean is also an int. The bool type is a subclass of the int type and True and False are its only instances:

issubclass(bool, int) # True

isinstance(True, bool) # True
isinstance(False, bool) # True

If boolean values are used in arithmetic operations, their integer values (1 and 0 for True and False) will be used to return an integer result:

True + False == 1 # 1 + 0 == 1
True * True  == 1 # 1 * 1 == 1

Numbers

• int: Integer number

a = 2
   b = 100
   c = 123456789
   d = 38563846326424324

Integers in Python are of arbitrary sizes.

Note: in older versions of Python, a `long` type was available and this was distinct from `int`. The two have been unified.

• float: Floating point number; precision depends on the implementation and system architecture, for CPython the float datatype corresponds to a C double.

a = 2.0
b = 100.e0
c = 123456789.e1

• complex: Complex numbers

a = 2 + 1j
b = 100 + 10j

The \\<, <=, \\> and >= operators will raise a TypeError exception when any operand is a complex number.

Strings in Python 3

• str: a unicode string. The type of 'hello'
• bytes: a byte string. The type of b'hello'

Strings in Python 2