modifying standard library functionality (difflib)

[Bruno Desthuilliers]

Vlastimil Brom a écrit :
> 
> Many thanks for your insights!
> Just now, I am the almost the only user of this script, hence the
> consequences of version mismatches etc. shouldn't (directly) affect
> anyone else, fortunately.

So far so good.

> However, I'd like to ask for some clarification about monkeypatching -
> With "directly replace" I  meant something like the following scenario:
> 
> import difflib
> ....
> def tweaked__chain_b(self):
>     # modified code of the function __chain_b copy from Lib\difflib.py
>     ...
> 
> difflib.SequenceMatcher._SequenceMatcher__chain_b = tweaked__chain_b
> 
> I thought, this would qualify as monkeypatching,

It does, indeed

> but I am apparently
> missing some distinction between "patching the ... code inplace"  and
> "monkeypatching".

"patching source code" canonically means "physically" modifying the 
original source file. Monkeypatching - which can only be done in some 
dynamic languages - is what you're doing above, ie dynamically replacing 
a given feature at runtime.

> By subclassing (which I am using just now in the code)

If it already works and you don't have to care too much about possible 
compat issues with different difflib versions, then look no further.