Handling Exceptions

Handling exceptions is a big thing to look out for in your code. Here is a list of exceptions you may run into while using the module:

• LoginError

• FilterError

• ImportError

See also

This section does not talk about why these exceptions occur or what they are, but how to handle them. See here for help on these exceptions and errors.

So, let’s say you want to prompt the user to input their credentials into the console and it tells them how many assignments they have due soon. Maybe something that looks like this:

from igrade import Client

client = Client()
username = input('What is your iGradePlus username? ')
password = input('What is your iGradePlus password? ')

client.login_with_credentials(username, password)
num_assignments = len(client.get_upcoming_assignments())

print(f'\nYou have {num_assignments} assignments due soon!')

client.close()

But, here’s the problem: if the user inputs the wrong credentials, it throws an error! Well, there is a way to catch them. All you need to do is import the exceptions.py file from the igrade module. Here is the first step:

from igrade import exceptions

And the next step is to wrap the problematic code inside of a try block. In this case, client.login_with_credentials(). After that, you put the exception that occurs in the console inside the except clause, like so:

try:
   client.login_with_credentials(username, password)
except exceptions.LoginError:  # exception you want to catch
   print('You input the wrong credentials. Please try again!')
   quit()  # keep program from continuing

And that is how easy it is to fix! After that, the new code should look something like this:

from igrade import Client
from igrade import exceptions

client = Client()
username = input('What is your iGradePlus username? ')
password = input('What is your iGradePlus password? ')

try:
    client.login_with_credentials(username, password)
except exceptions.LoginError:
    print('You input the wrong credentials. Please try again!')
    quit()

num_assignments = len(client.get_upcoming_assignments())

print(f'\nYou have {num_assignments} assignments due soon!')
client.close()