interactive_exception_handling

interactive_exception_handling.py

"""
Description: 
This script enhances the Python interactive console (REPL) by introducing
a custom exception handling mechanism. It leverages the built-in InteractiveConsole 
and InteractiveInterpreter classes and overrides the 'showtraceback' method 
for personalized exception handling. This enables more flexible control over 
how exceptions are dealt with in the console, and can be particularly useful for 
debugging or for enhancing console output in specific applications.
"""
import sys
import traceback
from code import InteractiveInterpreter, InteractiveConsole


class MyInterpreter(InteractiveInterpreter):
    """ https://github.dev/python/cpython/blob/7f963bfc79a515dc9822ebddbfb1b5927d2dda09/Lib/code.py#L150-L150
    """
    def showtraceback(self):
        """Display the exception that just occurred.

        We remove the first stack item because it is our own code.

        The output is written by self.write(), below.

        """
        print("here")
        sys.last_type, sys.last_value, last_tb = ei = sys.exc_info()
        sys.last_traceback = last_tb
        sys.last_exc = ei[1]
        try:
            lines = traceback.format_exception(ei[0], ei[1], last_tb.tb_next)
            if sys.excepthook is sys.__excepthook__:
                print("here if")
                self.write(''.join(lines))
            else:
                # If someone has set sys.excepthook, we let that take precedence
                # over self.write
                print("here else")
                sys.excepthook(ei[0], ei[1], last_tb)
        finally:
            last_tb = ei = None


class MyConsole(InteractiveConsole):
    def __init__(self, locals=None, filename="<console>"):
        self.interpreter = MyInterpreter()
        super().__init__(locals, filename)

    def showsyntaxerror(self, filename=None):
        self.interpreter.showsyntaxerror(filename)

    def showtraceback(self):
        self.interpreter.showtraceback()

# def myhook(type, value, traceback):
#     print('Hello, World!', file=sys.stderr)

if __name__ == "__main__":
    # sys.excepthook = myhook
    console = MyConsole()
    console.interact()