Welcome to the basics of Python programming! Python is a versatile and popular programming language used for various applications, from web development to data analysis.
Getting Started
Before diving into Python, make sure you have Python installed on your system. You can download and install Python from the official Python website.
Hello World
Your first Python program should be a simple "Hello World" script. Here's an example:
print("Hello, World!")
Save this script as hello_world.py
and run it using the Python interpreter. You should see the following output:
Hello, World!
Variables and Data Types
In Python, variables are used to store data. Python has several data types, including integers, floating-point numbers, strings, and booleans.
Variables
Variables are defined using the assignment operator (=
). For example:
name = "John Doe"
age = 30
is_student = False
Data Types
- String: A sequence of characters. For example,
"Python"
. - Integer: A whole number. For example,
5
. - Float: A number with a decimal point. For example,
3.14
. - Boolean: A value that can be either
True
orFalse
.
Control Structures
Python has various control structures for decision-making and repetition.
If-Else
if age > 18:
print("You are an adult.")
else:
print("You are not an adult.")
For Loop
for i in range(5):
print(i)
While Loop
count = 0
while count < 5:
print(count)
count += 1
Functions
Functions are blocks of code that can be reused. They help in organizing and structuring your code.
Defining a Function
def greet(name):
print(f"Hello, {name}!")
greet("Alice")
Parameters and Arguments
Functions can have parameters and arguments. Parameters are variables defined in the function definition, and arguments are the values passed to the function when it is called.
Lists
Lists are ordered collections of items. They can contain different types of data.
Accessing Elements
my_list = [1, 2, 3, 4, 5]
print(my_list[0]) # Output: 1
Adding Elements
my_list.append(6)
print(my_list) # Output: [1, 2, 3, 4, 5, 6]
List Comprehensions
List comprehensions provide a concise way to create lists.
squares = [x ** 2 for x in range(1, 6)]
print(squares) # Output: [1, 4, 9, 16, 25]
Dictionaries
Dictionaries are unordered collections of key-value pairs.
Accessing Elements
my_dict = {"name": "John", "age": 30}
print(my_dict["name"]) # Output: John
Adding Elements
my_dict["city"] = "New York"
print(my_dict) # Output: {'name': 'John', 'age': 30, 'city': 'New York'}
Modules and Packages
Python has a vast ecosystem of modules and packages for various tasks.
Importing Modules
import math
print(math.sqrt(16)) # Output: 4.0
Importing Specific Functions
from math import sqrt
print(sqrt(25)) # Output: 5.0
For more information on modules and packages, check out the Python documentation.
Conclusion
Congratulations! You've learned the basics of Python programming. Continue exploring and expanding your knowledge by experimenting with the code examples and reading more about Python.