2.2 Python Core Data Types (BT101CO)

These represent numbers and are the most basic building blocks for mathematical problem-solving.

• Integer (int): Represents whole numbers (positive, negative, or zero) without a decimal point.
  Example: 10, -5, 1002.
• Floating Point (float): Represents real numbers with a decimal point.
  Example: 10.5, 3.14, -0.001.
• Complex (complex): Used for scientific calculations, represented as $a + bj$, where $a$ is the real part and $b$ is the imaginary part.
  Example: 3 + 4j.

Sequences are ordered collections of items. A critical concept here is the difference between mutable (changeable) and immutable (unchangeable) sequences.

• String (str): An immutable sequence of characters enclosed in single (' '), double (" "), or triple (''' ''') quotes.
• List (list): A mutable ordered collection of items (can be of different types). Defined using square brackets [].
  Example: [1, "Ashok", 3.4].
• Tuple (tuple): An immutable ordered collection. Once created, its elements cannot be changed. Defined using parentheses ().
  Example: (1, 2, 3).

Dictionary (dict): An unordered collection of key-value pairs. Each key must be unique and is used to retrieve its corresponding value. Defined using curly braces {}.

Example: {"Name": "Ashok", "RollNo": 101}.

Set (set): An unordered collection of unique items. Sets are used to eliminate duplicate values and perform mathematical set operations like union and intersection.

Example: {1, 2, 3, 3} becomes {1, 2, 3}.

Boolean (bool): Represents one of two values: True or False. These are essential for control flow (if-statements and loops). Note that in Python, True is internally treated as 1 and False as 0.

None: A special data type that represents the absence of a value or a null value. It is often used to initialize variables that will be assigned a value later.