Write a Python program to find the factorial of a number using an iterative function instead of recursion.

Write a Python program to use map() with a lambda function to convert a list of temperatures from Celsius to Fahrenheit.

Write a Python function to check if a given number is a prime number.

Write a Python function to flatten a nested list using recursion.

Write a Python function that takes another function as an argument and applies it to every element in a list.

A module in Python is simply a file containing Python definitions and statements. A module can define functions, classes, and variables. It can also include runnable code.

By organizing your code into modules, you can keep related code together and reuse it across multiple programs.

# greetings.py
def hello(name):
    print(f"Hello, {name}!")

def goodbye(name):
    print(f"Goodbye, {name}!")

To use a module in another Python program, you need to import it using the import keyword.

import greetings

greetings.hello("Alice")   # Output: Hello, Alice!
greetings.goodbye("Bob")   # Output: Goodbye, Bob!

You can also import specific functions or variables from a module using from.

from greetings import hello

hello("Alice")   # Output: Hello, Alice!

Python comes with a large standard library of modules that you can use without needing to install them. The standard library includes modules for various tasks such as working with files, handling dates and times, performing mathematical operations, and much more.

import math

result = math.sqrt(16)
print(result)  # Output: 4.0

from datetime import datetime

current_time = datetime.now()
print(current_time)  # Output: 2024-09-12 10:23:00 (example output)

You can easily create your own modules. All you need to do is save your Python code in a .py file. Later, you can import and use this module in other programs.

def add(a, b):
    return a + b

def subtract(a, b):
    return a - b

import math_tools

print(math_tools.add(3, 5))  # Output: 8
print(math_tools.subtract(10, 4))  # Output: 6

Importing with Aliases: You can give an alias to a module or function while importing it to simplify the code or avoid naming conflicts.

import math as m

print(m.sqrt(25))  # Output: 5.0

Importing All Names from a Module: You can use the * symbol to import everything from a module

from math import *

print(sqrt(9))  # Output: 3.0

However, importing everything this way is discouraged as it can lead to confusion if you have multiple imports with the same function names.

A package is a collection of related modules. A package is just a directory that contains multiple Python files (modules) and an __init__.py file. The __init__.py file makes the directory a Python package.

math_package/
    __init__.py
    basic_operations.py
    advanced_operations.py

__init__.py: This file can be empty or contain initialization code for the package.

Modules (basic_operations.py, advanced_operations.py): The Python files inside the package contain your functions or classes.

my_package/
    __init__.py
    utilities.py

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

from my_package import utilities

print(utilities.greet("Alice"))  # Output: Hello, Alice!

pip install package_name

pip install requests

import requests

response = requests.get("https://api.github.com")
print(response.status_code)  # Output: 200

import math

print(dir(math))  # Lists all functions and constants in the math module
help(math.sqrt)   # Provides documentation for the sqrt function

file = open("filename", "mode")

file = open("example.txt", "r")

file.close()

with open("example.txt", "r") as file:
    content = file.read()
    print(content)  # File is automatically closed after the block

with open("example.txt", "r") as file:
    content = file.read()
    print(content)  # Prints the entire file content

with open("example.txt", "r") as file:
    line = file.readline()
    print(line)  # Prints the first line of the file

with open("example.txt", "r") as file:
    lines = file.readlines()
    print(lines)  # Prints all lines in a list

with open("output.txt", "w") as file:
    file.write("Hello, World!\n")
    file.write("This is a Python program.\n")

lines = ["First line\n", "Second line\n", "Third line\n"]

with open("output.txt", "w") as file:
    file.writelines(lines)

with open("output.txt", "a") as file:
    file.write("This line will be appended.\n")

with open("image.jpg", "rb") as file:
    binary_content = file.read()
    print(binary_content)  # Outputs the binary content of the image

with open("new_image.jpg", "wb") as file:
    file.write(binary_content)  # Writes binary content to a new file

try:
    with open("non_existent_file.txt", "r") as file:
        content = file.read()
except FileNotFoundError:
    print("File not found. Please check the filename.")

with open("example.txt", "r") as file:
    print(file.tell())  # Prints the current position of the file pointer
    file.seek(0)  # Moves the pointer to the beginning of the file
    print(file.read())

Write a Python program to count the number of words in a text file.

Write a Python program that copies the contents of one file into another file.

Write a Python program that reads the content of a file and writes it to a new file in reverse order

Write a Python program that opens a binary file (such as an image) and creates a copy of it.

Write a Python program that reads a text file and counts the frequency of each character in the file.