Raise ValueError if file not found

Question

I would like to raise a ValueError if a file is not found. Currently I have the following:

def read_file(filename):
    try:
        with open(filename, "r") as f: 
        #do something
    except ValueError:
        print("File not found")

However, this just returns a FileNotFoundError: if the file isn't found

Answer 1

Catch IOError instead, and inside the except block, raise a ValueError .

try:
    with open(filename, "r") as f: 
    #do something
except IOError:
    raise ValueError("File not found")

Answer 2

You could be a little more explicit and raise ValueError as Python provides the ability to not only catch built-in exceptions but raise them too.

def read_file(filename):
    try:
        with open(filename, "r") as f:
            pass # do something
    except FileNotFoundError:
        raise ValueError("File not found")