Python Basics

Introduction to Python

What is Python?

Python is a high-level, interpreted programming language. This is a simple Python code:

Code

print('Hello, World!')

Variables and Data Types

In Python, variables can store data of different types without explicitly declaring the type.

For example:

Code

integer_variable = 10
string_variable = 'Hello'
float_variable = 10.5

float_variable

10.5

Control Structures

Python supports the usual logical conditions from mathematics:

Code

# Equals: a == b
# Not Equals: a != b
# Less than: a < b
# Less than or equal to: a <= b
# Greater than: a > b
# Greater than or equal to: a >= b

These conditions can be used in several ways, most commonly in ‘if statements’ and loops.

Code

# if statement:
if 5 > 2:
    print('Five is greater than two!')

Functions

A function is a block of code which only runs when it is called.

You can pass data, known as parameters, into a function.

A function can return data as a result.

Code

# Defining a function:
def my_function():
    print('Hello from a function')

# Calling a function:
my_function()

Lists and Dictionaries

A list is a collection which is ordered and changeable.

A dictionary is a collection which is unordered, changeable and indexed.

Code

# List example:
my_list = ['apple', 'banana', 'cherry']

# Dictionary example:
my_dict = {'name': 'John', 'age': 36}