Python Programming Basics

1/20/2024• 3 min read

Introduction to Python programming language fundamentals

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Python Programming Basics

Python is a high-level, interpreted programming language known for its simplicity and readability.

Introduction

Python was created by Guido van Rossum and first released in 1991. It emphasizes code readability and allows programmers to express concepts in fewer lines of code.

Key Features

  • Simple and Easy to Learn: Clean syntax, easy to read
  • Interpreted Language: No compilation needed
  • Dynamically Typed: No need to declare variable types
  • High-Level Language: Abstracts low-level details
  • Extensive Libraries: Rich standard library and third-party packages

Basic Syntax

Variables and Data Types

# Numbers
x = 10          # Integer
y = 3.14        # Float
z = 5 + 3j      # Complex

# Strings
name = "Python"
message = 'Hello, World!'

# Boolean
is_active = True
is_complete = False

# Lists
numbers = [1, 2, 3, 4, 5]
fruits = ["apple", "banana", "orange"]

# Dictionaries
person = {"name": "John", "age": 30}

Control Flow

# If-else statements
if x > 10:
    print("Greater than 10")
elif x == 10:
    print("Equal to 10")
else:
    print("Less than 10")

# Loops
for i in range(5):
    print(i)

while x > 0:
    print(x)
    x -= 1

Functions

def greet(name):
    return f"Hello, {name}!"

# Lambda functions
square = lambda x: x ** 2

Classes and Objects

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age
    
    def introduce(self):
        return f"I'm {self.name}, {self.age} years old"

person = Person("Alice", 25)
print(person.introduce())

Python Collections

Lists

my_list = [1, 2, 3]
my_list.append(4)
my_list.insert(0, 0)
my_list.remove(2)

Tuples

Immutable sequences: (1, 2, 3)

Sets

Unordered collections of unique elements: {1, 2, 3}

Dictionaries

Key-value pairs: {"key": "value"}

File Handling

# Reading files
with open("file.txt", "r") as f:
    content = f.read()

# Writing files
with open("file.txt", "w") as f:
    f.write("Hello, World!")

Exception Handling

try:
    result = 10 / 0
except ZeroDivisionError:
    print("Cannot divide by zero")
except Exception as e:
    print(f"An error occurred: {e}")
finally:
    print("This always executes")

List Comprehensions

# Traditional way
squares = []
for x in range(10):
    squares.append(x**2)

# List comprehension
squares = [x**2 for x in range(10)]

Popular Python Libraries

  • NumPy: Numerical computing
  • Pandas: Data manipulation and analysis
  • Matplotlib: Data visualization
  • Django/Flask: Web development
  • Requests: HTTP library
  • Scikit-learn: Machine learning

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