Python Data Types

A data type defines the kind of value stored in a Python variable. Python automatically determines the data type when a value is assigned to a variable. The type() function can be used to find the type of a value.

Types of Data Types in Python

Python provides several built-in data types. The commonly used types are:

1. Numeric Data Types

Python provides three main numeric data types: int, float and complex.

Integer (int)

The int type represents whole numbers without a decimal part. Integers can be positive, negative or zero.

age = 20
temperature = -5
count = 0

print(type(age))
print(type(temperature))

<class 'int'>
<class 'int'>

Float (float)

The float type represents numbers containing a decimal point.

price = 99.50
percentage = 85.75

print(type(price))
print(type(percentage))

<class 'float'>
<class 'float'>

Complex (complex)

A complex number has a real part and an imaginary part. Python uses j to represent the imaginary part.

z = 2 + 3j

print(z)
print(type(z))

(2+3j)
<class 'complex'>

Numeric data types are covered in more detail in the next tutorial.

2. Boolean Data Type

The bool type represents one of two values: True or False. Boolean values are commonly used in conditions and decision-making statements.

is_student = True
is_logged_in = False

print(is_student)
print(type(is_student))

True
<class 'bool'>

Boolean values are also produced by comparison expressions.

age = 20

print(age >= 18)
print(age == 15)

True
False

3. String Data Type

The str type is used to store text. Strings can be written using single quotes, double quotes or triple quotes.

name = "Rahul"
city = 'Noida'

print(name)
print(city)
print(type(name))

Rahul
Noida
<class 'str'>

Strings are sequences of characters and support indexing and slicing.

text = "Python"

print(text[0])
print(text[0:3])

P
Pyt

4. List Data Type

A list is an ordered and mutable collection of items. A list can contain values of different data types.

numbers = [10, 20, 30, 40]

print(numbers)
print(numbers[0])

numbers.append(50)
print(numbers)

[10, 20, 30, 40]
10
[10, 20, 30, 40, 50]

5. Tuple Data Type

A tuple is an ordered collection of items. Unlike a list, a tuple is immutable, which means its elements cannot normally be changed after creation.

numbers = (10, 20, 30)

print(numbers)
print(numbers[1])
print(type(numbers))

(10, 20, 30)
20
<class 'tuple'>

6. Range Data Type

The range type represents a sequence of numbers and is commonly used with loops.

numbers = range(1, 5)

for n in numbers:
    print(n)

1
2
3
4

7. Set Data Type

A set is an unordered collection of unique elements. Duplicate values are automatically removed.

numbers = {10, 20, 20, 30}

print(numbers)
print(type(numbers))

{10, 20, 30}
<class 'set'>

8. Frozen Set

A frozenset is an immutable version of a set.

numbers = frozenset([10, 20, 30])

print(numbers)
print(type(numbers))

9. Dictionary Data Type

A dictionary stores data in key-value pairs. Each key is used to access its corresponding value.

student = {
    "name": "Rahul",
    "age": 20,
    "marks": 85
}

print(student["name"])
print(student["marks"])

Rahul
85

10. Bytes Data Type

The bytes type represents an immutable sequence of bytes. It is commonly used when working with binary data.

data = b"Python"

print(data)
print(type(data))

b'Python'
<class 'bytes'>

11. Bytearray Data Type

The bytearray type is similar to bytes but its contents can be modified.

data = bytearray([65, 66, 67])

data[0] = 68

print(data)

bytearray(b'DBC')

12. Memoryview Data Type

A memoryview object provides a view of the memory of a bytes-like object without making a copy of the data.

data = bytearray("Python", "utf-8")
view = memoryview(data)

print(view[0])
print(type(view))

80
<class 'memoryview'>

13. NoneType

The None value represents the absence of a value. Its data type is NoneType.

result = None

print(result)
print(type(result))

None
<class 'NoneType'>

Checking the Data Type

The type() function is used to determine the type of an object.

a = 10
b = 10.5
c = "Python"
d = [1, 2, 3]

print(type(a))
print(type(b))
print(type(c))
print(type(d))

Type Conversion

Python provides built-in functions such as int(), float() and str() to convert compatible values from one data type to another.

x = "100"

a = int(x)
b = float(x)
c = str(50)

print(a)
print(b)
print(c)

100
100.0
50

Mutable and Immutable Data Types

Python data types can also be classified as mutable and immutable.

Example of Mutable Data Type

numbers = [10, 20, 30]

numbers[0] = 100

print(numbers)

[100, 20, 30]

Example of Immutable Data Type

A string cannot be changed directly after it has been created.

name = "Python"

# A new string is created
name = "Java"

print(name)

Java