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.

Welcome to Day 11 of the "Noob to Pro in Python" course! Today, we’ll focus on exceptions in Python, learning how to handle errors effectively. Exception handling is crucial for writing robust, error-free programs that behave predictably even when things go wrong. You’ll understand how to catch exceptions, raise errors, and use custom exceptions.

An exception is an event that occurs during the execution of a program that disrupts its normal flow. When a Python program encounters an error, it raises an exception, which terminates the program unless the error is handled.

try:
    # Code that might raise an exception
    risky_code()
except ExceptionType:
    # Code to handle the exception
    handle_exception()

try:
    result = 10 / 0
except ZeroDivisionError:
    print("Cannot divide by zero!")

try:
    file = open("non_existent_file.txt", "r")
    result = 10 / 0
except FileNotFoundError:
    print("File not found!")
except ZeroDivisionError:
    print("Cannot divide by zero!")

try:
    result = 10 / 2
except ZeroDivisionError:
    print("Cannot divide by zero!")
else:
    print("Division successful:", result)

try:
    file = open("example.txt", "r")
    result = 10 / 0
except ZeroDivisionError:
    print("Cannot divide by zero!")
finally:
    print("This will always be executed.")
    file.close()

def check_age(age):
    if age < 18:
        raise ValueError("Age must be 18 or above.")
    return "Valid age"

try:
    check_age(16)
except ValueError as e:
    print(e)

class InvalidAgeError(Exception):
    """Custom exception for invalid age."""
    pass

def check_age(age):
    if age < 18:
        raise InvalidAgeError("You must be at least 18 years old.")
    return "Valid age"

try:
    check_age(16)
except InvalidAgeError as e:
    print(e)

try:
    raise ValueError("An error occurred")
except Exception as e:
    print("Caught an exception:", e)