Erratum

Erratum is a python package that aims to make it easy to build in user friendly error messages into your project. Let’s look at the following example:

>>> my_square_root(-1)
<ipython-input-3-a8d1f1b285c7> in my_square_root(n)
      5
      6     if n < 0:
----> 7         raise ValueError("You can only take the square root of a positive number")
      8
      9     return math.sqrt(n)

ValueError: You can only take the square root of a positive number
More info --> https://github.com/alcarney/erratum

As you can see we get the error message as passed to the exception but we also get a link to a webpage where we can find more information about the error and what we need to do to fix it.

How? Well let’s look at the implementation of my_square_root

import math
from erratum import Error

class SqrtError(Error):
    url = "https://github.com/alcarney/erratum"

@SqrtError
def my_square_root(n):

    if n < 0:
        raise ValueError("You can only take the square root of a positive number")

    return math.sqrt(n)

Here we declare our error SqrtError by subclassing the Error class which allows us to set the url the user gets sent to find out more about the error. Then it is simply of decorating any function we want the function to apply to with the annotate method. This will cause any exception that is thrown from within the function to be tagged with the more info link.