Question

File reading, calculating, and exception error handling questions. Assume a file contains a series of integers in file numbers.txt. You can find the file (numbers.txt) in canvas. First, copy the file into the same directory as this python program. Then, write a program that calculates the average of all the numbers stored in the file. Finally, your program needs to handle the exception with appropriate error messages. When everything goes well, the average of all the numbers = 4.75 Modify the program to handle the following exceptions with messages: (hint: modify your code one at a time to trigger one of the following exceptions and restore it before simulating another error.

a) IOErroer: An error occurred while trying to read the file. [Errno 2] No such file or directory: 'numbers.txt'
b) ValueError : Non-numeric data found in the file could not convert string to float: 'a \ '
c) Exception: An error occurred float division by zero

Answer 1

The student's task is to write a Python program that calculates the average of integers from a file, handling various exceptions such as FileNotFoundError, ValueError, and ZeroDivisionError. The code provided outlines how to open the file, read and parse integers, calculate the average, and handle these exceptions with appropriate error messages.

Step-by-step explanation:

To calculate the average of the numbers from the file numbers.txt, we'll write a Python program that reads the integers from the file, totals them, counts them, and computes the average. We need to handle various exceptions to ensure the program operates correctly even when errors occur. Below is a step-by-step example of how you could handle this in your program:

1. Open the file using a with statement to ensure the file gets closed properly.
2. Read each line from the file, convert it to an integer, and accumulate the values while counting them.
3. If the file is not found, catch the IOError and display an appropriate message.
4. When encountering data that cannot be converted to an integer, catch the ValueError and display an error message.
5. If no data is available to calculate an average (e.g., an empty file), catch the zero division error and produce an error message.

Here is a Python code example of how this could be implemented:

try:
with open('numbers.txt', 'r') as file:
total = 0
count = 0
for line in file:
try:
number = float(line)
total += number
count += 1
except ValueError:
print("Non-numeric data found in the file could not convert string to float.")
average = total / count
print("The average of all the numbers is", average)
except IOError:
print("An error occurred while trying to read the file. No such file or directory: 'numbers.txt'")
except ZeroDivisionError:
print("An error occurred: float division by zero.")
except Exception as e:
print("An error occurred", e)