Python Data Types

Data types in Python define what type of values a variable can hold. They will specify how the data should be stored, accessed, and manipulated in a program. Python has many pre-built data types, but all of them can broadly be categorized based on their purposes and behaviors:

1. Numeric types

a) int (Integer)

• Represents whole numbers (either positive or negative) that don’t have a decimal point.
• Unlimited precision.
• Examples:

      x = 10      # Positive integer
      y = -200    # Negative integer

b) float (Floating Point)

• Reprents real numbers, but with a decimal point
• Examples:

      pi = 3.14159
      e = -2.71

c) complex (Complex Numbers)

• Represents numbers as a + bj where both a (real part) and b (imaginary part) are floats.
• Examples:

      z = 3 + 4j
      print(z.real)    # 3.0
      print(z.imag)    # 4.0

2. Sequence Types

a) str (String)

• Used to store text data.
• Enclosed in single ' ', double " ", or triple quotes ''' ''' / "" "".
• Immutable.
• Examples:

       name = "Python"
       multiline = '''This is 
       a multiline string.'''

b) list

• Ordered, mutable collection of items.
• It can hold mixed data types.
• Examples:

      fruits = ["apple", "banana", "cherry"]
      mixed = [1, "Python", 3.14, True]

c) tuple

• Ordered, unmodifiable collection of objects.
• Useful for static data.
• Examples:

      coordinates = (10, 20)
      person = ("John", 30)

d) range

• Represents an immutable sequence of numbers.
• Often used in loops.
• Examples:

      r = range(5)    # 0, 1, 2, 3, 4
      r2 = range(2, 10, 2)    # 2, 4, 6, 8

3. Mapping Type

dict (Dictionary)

• An unordered, mutable collection of key-value pairs.
• Keys must be unique and immutable (strings, numbers, or tuples).
• Examples:

      student = {"name": "Alice", "age": 25, "grade": "A"}

4. Set Types

a) set

• An unordered collection of unique elements.
• It is mutable.
• Examples:

      numbers = {1, 2, 3, 3, 4}    # {1, 2, 3, 4} 

b) frozenset

• Immutable version of set.
• Examples:

      frozen = frozenset([1, 2, 3, 4])

5. Boolean Type

bool

• Represents one of two values: True or False.
• Internally, True is 1 and False is 0.
• Examples:

      is_active = True
      is_admin = False

6. Binary Types

a) bytes

• Immutable sequence of bytes.
• Examples:

      b = b"hello"

b) bytearray

• Mutable sequence of bytes.
• Examples:

      ba = bytearray(b"hello")

c) memoryview

• Allows you to access the memory of another binary object without copying.
• Examples:

      mv = memoryview(b"hello")

7. None Type

NoneType

• It is represented as the absence of any value or a null value.
• Used as the default return value of those functions which explicitly return nothing.
• Example:

      x = None

How to Check the Data Type of a Variable

Use the type() function:

      x = 10

      print(type(x))   # <class 'int'>

      num = 10
      num_str = str(num)   # Converts integer to string