Notes – Python Data Types

Data types in Python define the kind of data a variable can hold. Since Python is dynamically typed, you don’t need to specify data types explicitly—Python detects them automatically.

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1. Numeric Data Types

These are used to store numbers.

Data Type	Description	Example
int	Integer (whole numbers)	x = 10
float	Decimal numbers	y = 3.14
complex	Complex numbers	z = 2 + 3j

Example:

x = 10         # Integer
y = 3.14       # Float
z = 2 + 3j     # Complex

print(type(x))  # Output: <class 'int'>
print(type(y))  # Output: <class 'float'>
print(type(z))  # Output: <class 'complex'>

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2. Sequence Data Types

These store ordered collections of data.

Data Type	Description	Example
str	String (text)	"Hello, Python!"
list	Ordered, mutable collection	[1, 2, 3, "apple"]
tuple	Ordered, immutable collection	(10, 20, "banana")

Example:

text = "Python"       # String
numbers = [1, 2, 3]   # List
coordinates = (4, 5)  # Tuple

print(type(text))       # Output: <class 'str'>
print(type(numbers))    # Output: <class 'list'>
print(type(coordinates)) # Output: <class 'tuple'>

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3. Set Data Types

Used to store unique, unordered collections.

Data Type	Description	Example
set	Unordered, unique elements	{1, 2, 3, 3, 4}
frozenset	Immutable set	frozenset({1, 2, 3})

Example:

my_set = {1, 2, 3, 3, 4}  # Duplicates removed
f_set = frozenset(my_set)  # Immutable set

print(my_set)  # Output: {1, 2, 3, 4}
print(type(f_set))  # Output: <class 'frozenset'>

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4. Mapping Data Type

Stores key-value pairs.

Data Type	Description	Example
dict	Stores key-value pairs	{"name": "John", "age": 25}

Example:

student = {"name": "Alice", "age": 21, "course": "Python"}
print(student["name"])  # Output: Alice

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5. Boolean Data Type

Represents True or False values.

Data Type	Description	Example
bool	True or False values	is_active = True

Example:

is_python_easy = True
print(type(is_python_easy))  # Output: <class 'bool'>

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6. Binary Data Types

Used to handle binary data like images or files.

Data Type	Description	Example
bytes	Immutable byte sequences	b"Hello"
bytearray	Mutable byte sequences	bytearray(5)
memoryview	View memory of an object	memoryview(b"Hello")

Example:

b = bytes([65, 66, 67])
print(b)  # Output: b'ABC'

ba = bytearray([65, 66, 67])
ba[0] = 97
print(ba)  # Output: bytearray(b'aBC')

mv = memoryview(b"Hello")
print(mv[0])  # Output: 72 (ASCII value of 'H')