Dealing with files and Exception Handling in Python

We have try, except, raise and finally as our code blocks to handle the error or an exceptions

To understand the concept easily -

• Each block of code works as an if, elif, else block

# There is a built in method in python called open("")
# file = open("orders.text") # Looks for the file called orders.text
# keyword try
try:
    file = open("orders.text")
    print("file is found")
except FileNotFoundError as errmsg:
    print(f"The above block of code was not executed {errmsg}")
    #raise
finally:
    print("Your task is to read the data and display it as a list")

• Please ensure to create an orders.text if does not exist

Mode	Description
'r'	This is the default mode. It Opens file for reading.
'w'	This Mode Opens file for writing. If file does not exist, it creates a new file. If file exists it truncates the file.
'x'	Creates a new file. If file already exists, the operation fails.
'a'	Open file in append mode. If file does not exist, it creates a new file.
't'	This is the default mode. It opens in text mode.
'b'	This opens in binary mode.
'+'	This will open a file for reading and writing (updating)

It is worth noting that the + operator can be used with

def open_using_with_and_print(file):
    try:
        with open(file, "r") as file:
            for line in file.readlines():
                print(line.rstrip('\n'))
    except FileNotFoundError:
        print("file cannot be found or directory is incorrect, please check the details provided")
        raise
    finally:
        print("\nPlease chose the items from the list  and enjoy your HAPPY MEAL")
open_using_with_and_print("orders.text")

• Let's add an item to our orders.text

def write_to_file(file, order_item):
    try:
        with open(file, "w") as file:
            file.write(order_item + '\n')
    except FileNotFoundError:
        print("file cannot be found or directory is incorrect, please check the details provided")
        raise

write_to_file("order.txt", "Ice Cream")