Data Types in Python

Python has several built-in data types, broadly grouped as:

Numeric Types

a = 10          # int      — whole numbers
b = 3.14        # float    — decimal numbers
c = 2 + 3j      # complex  — real + imaginary part
print(type(a), type(b), type(c))

Boolean

flag = True
print(type(flag))    # <class 'bool'>
print(True + True)   # 2  -> bool is a subtype of int

Sequence Types

s = "Python"                 # str   — ordered, immutable characters
lst = [1, 2, 3]                # list  — ordered, mutable
tup = (1, 2, 3)                # tuple — ordered, immutable
r = range(5)                   # range — sequence of numbers

Mapping Type

d = {"name": "Ravi", "age": 21}   # dict — key-value pairs

Set Types

st = {1, 2, 3}                 # set        — unordered, unique, mutable
fs = frozenset({1, 2, 3})      # frozenset  — unordered, unique, immutable

None Type

x = None
print(type(x))   # <class 'NoneType'>

Type Conversion (Casting)

print(int("25"))       # 25   (str -> int)
print(float(10))       # 10.0 (int -> float)
print(str(3.14))       # '3.14' (float -> str)
print(list("abc"))     # ['a', 'b', 'c']
print(bool(0))          # False
print(bool(1))          # True

type() and isinstance()

x = 5
print(type(x) == int)       # True
print(isinstance(x, int))   # True (preferred, supports inheritance)