Python Basic Part 1 : Understanding Data Types and Variables

Data Types

A data type is a classification of data that determines the operations that can be performed on it and the types of values it can store. Python has several built-in data types, including:

a. Numeric Data Types : Numeric data types are used to store numeric values. Python has three numeric data types: integers, floating-point numbers, and complex numbers.

a = 19 #integer
b = 40.8 #floating-point number
c = 6 + 23b #complex number

• Integers: Integers are whole numbers that can be positive, negative, or zero. In Python, integers are represented by the int data type. For example: x = 19.
• Floating-Point Numbers: Floating-point numbers are decimal numbers that can be represented with a fractional part. In Python, floating-point numbers are represented by the float data type. For example: x = 40.8.
• Complex Numbers: Complex numbers are used to represent numbers with real and imaginary parts. In Python, complex numbers are represented by the complex data type. For example: x = 6 + 23b.

b. Text data type : Text data type is used to store text values. In Python, text data is represented by the str data type. For example: x = "ringo starr".

c. Boolean Data Type : Boolean data type is used to represent True or False values. In Python, boolean data is represented by the bool data type. For example: x = True.

d. Sequence Data Types : Sequence data types are used to store a collection of values. Python has three sequence data types: lists, tuples, and range objects.

• Lists: Lists are ordered collections of values that can be of any data type. In Python, lists are represented by the list data type. For example :

fruits = ['pineapple', 'banana', 'strawberry']

• Tuples : Tuples are ordered collections of values that are immutable, meaning they cannot be changed once created. In Python, tuples are represented by the tuple data type. For example : x = (4, 5, 6).
• Range Objects : Range objects are used to represent a sequence of numbers. In Python, range objects are represented by the range data type. For example: x = range(0, 15).
• Set Data Type: A set is an unordered collection of unique elements. Sets can have elements of different data types.

myset = {4, 5, 6, 7, 8}

e. Mapping Data Types : Mapping data types are used to store key-value pairs. Python has one mapping data type: dictionaries.

• Dictionaries: Dictionaries are unordered collections of key-value pairs. In Python, dictionaries are represented by the dict data type. For example: x = {"name": "Johanes", "age": 65}.

mydict = {'name': 'Johanes', 'age': 65}

Variables

A variable is a named location in memory that is used to store data. In Python, you don’t need to declare a variable before using it. You can simply assign a value to a variable, and Python will automatically create the variable and assign the value to it. For example:

x = 17
y = "Ringo"
print(x)
print(y)

In this example, we’ve created two variables: x and y. We've assigned the value 17 to x, and the value "Ringo" to y. Now, we can use these variables in our code. For example :

z = x + 8
print(y + " starr")