how to insert random error in a programming

[rusi]

On Oct 15, 9:00 pm, John Gordon <gor... at panix.com> wrote:
> In <mailman.2205.1350309347.27098.python-l... at python.org> Debashish Saha <silid... at gmail.com> writes:
>
> > how to insert random error in a programming?
>
> Open the program source file and replace the Nth character with a random
> character.

I'm reminded of a description of vi:

A program with two modes, one in which it beeps and the other in which
it corrupts your file.