myexceptions.py

# -*- coding: utf-8 -*-

#title:             myexceptions.py
#description:       Storage for my basic exceptiopns
#author:            Ricky Laney
#date:              20190125
#version:           0.0.1
#usage:             python -m myexceptions.py or import myexceptions.py
#notes:             
#python_version:    3.7.0
#==============================================================================

class Error(Exception):
    """Base class for exceptions in this module."""
    pass

class InputError(Error):
    """Exception raised for errors in the input.

    Attributes:
        expression -- input expression in which the error occurred
        message -- explanation of the error
    """

    def __init__(self, expression, message):
        self.expression = expression
        self.message = message

class TransitionError(Error):
    """Raised when an operation attempts a state transition that's not
    allowed.

    Attributes:
        previous -- state at beginning of transition
        next -- attempted new state
        message -- explanation of why the specific transition is not allowed
    """

    def __init__(self, previous, next, message):
        self.previous = previous
        self.next = next
        self.message = message