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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.


1. Numeric Data Types

These are used to store numbers.

Data TypeDescriptionExample
intInteger (whole numbers)x = 10
floatDecimal numbersy = 3.14
complexComplex numbersz = 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'>

2. Sequence Data Types

These store ordered collections of data.

Data TypeDescriptionExample
strString (text)"Hello, Python!"
listOrdered, mutable collection[1, 2, 3, "apple"]
tupleOrdered, 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'>

3. Set Data Types

Used to store unique, unordered collections.

Data TypeDescriptionExample
setUnordered, unique elements{1, 2, 3, 3, 4}
frozensetImmutable setfrozenset({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'>

4. Mapping Data Type

Stores key-value pairs.

Data TypeDescriptionExample
dictStores key-value pairs{"name": "John", "age": 25}

Example:

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

5. Boolean Data Type

Represents True or False values.

Data TypeDescriptionExample
boolTrue or False valuesis_active = True

Example:

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

6. Binary Data Types

Used to handle binary data like images or files.

Data TypeDescriptionExample
bytesImmutable byte sequencesb"Hello"
bytearrayMutable byte sequencesbytearray(5)
memoryviewView memory of an objectmemoryview(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')