Built-in Data Types

In Python, every value has a data type. A data type tells Python what kind of data a variable contains and what operations can be performed on it.

Python has several built-in data types.

Why Are Data Types Important?

Data types help Python understand how to store and process information.

For example:

name = "John" 
age = 25
            

Here:

• "John" is text (string)
• 25 is a number (integer)

Python automatically determines the data type when you assign a value to a variable.

Checking the Data Type

You can use the type() function to check the data type of any variable.

name = "John" 
print(type(name))
            

Output:

<class 'str'>
            

Let's look at each type one by one.

String (str)

Strings are used to store text.

Example

name = "Alice"print(type(name))
            

Output:

<class 'str'>
            

Strings can use single or double quotes.

name = 'Alice'
name = "Alice"
            

Both are valid.

Integer (int)

Integers are whole numbers without decimal points.

Example

age = 25
print(type(age))
            

Output:

<class 'int'>
            

Float (float)

Floats are numbers that contain decimal points.

Example

price = 19.99
print(type(price))
            

Output:

<class 'float'>
            

Complex Numbers (complex)

Complex numbers contain a real and an imaginary part.

Example

x = 3 + 4j
print(type(x))
            

Output:

<class 'complex'>
            

Complex numbers are commonly used in advanced mathematics and engineering.

Boolean (bool)

Boolean values represent either True or False.

Example

is_logged_in = True
print(type(is_logged_in))
            

Output:

<class 'bool'>
            

Booleans are often used in conditions and comparisons.

List (list)

A list is an ordered collection of items.

Lists can be modified after creation.

Example

fruits = ["Apple", "Banana", "Mango"]
print(type(fruits))
            

Output:

<class 'list'>
            

Lists can contain different data types:

data = ["John", 25, True]
            

Tuple (tuple)

A tuple is similar to a list, but it cannot be changed after creation.

Example

colors = ("Red", "Green", "Blue")
print(type(colors))
            

Output:

<class 'tuple'>
            

Use tuples when data should remain fixed.

Range (range)

The range() function generates a sequence of numbers.

Example

numbers = range(5)
print(type(numbers))
            

Output:

<class 'range'>
            

This creates:

0, 1, 2, 3, 4
            

Dictionary (dict)

A dictionary stores data in key-value pairs.

Example

student = { "name": "John", "age": 20 }
print(type(student))
            

Output:

<class 'dict'>
            

You can access values using keys:

print(student["name"])
            

Output:

John
            

Set (set)

A set is an unordered collection of unique values.

Example

numbers = {1, 2, 3, 4}
print(type(numbers))
            

Output:

<class 'set'>
            

Sets automatically remove duplicate values.

numbers = {1, 1, 2, 3}
            

Result:

{1, 2, 3}
            

Frozen Set (frozenset)

A frozenset is an immutable version of a set.

Example

numbers = frozenset([1, 2, 3])
print(type(numbers))
            

Output:

<class 'frozenset'>
            

Once created, it cannot be modified.

Bytes (bytes)

Bytes are used to store binary data.

Example

data = b"Hello"
print(type(data))
            

Output:

<class 'bytes'>
            

Bytearray (bytearray)

A bytearray is similar to bytes but can be modified.

Example

data = bytearray(5)
print(type(data))
            

Output:

<class 'bytearray'>
            

Memoryview (memoryview)

A memoryview provides access to the internal memory of an object without copying it.

Example

data = memoryview(bytes(5))
print(type(data))
            

Output:

<class 'memoryview'>
            

This type is mostly used in advanced applications.

NoneType

The value None represents the absence of a value.

Example

x = None
print(type(x))
            

Output:

<class 'NoneType'>
            

None is commonly used as a placeholder value.

Type Conversion

You can convert one data type into another using Python's built-in functions.

Convert Integer to String

age = 25 text = str(age)
            

Convert String to Integer

number = int("100")
            

Convert Integer to Float

price = float(10)
            

Convert Float to Integer

price = int(10.99)