Well said! On Wed, Dec 4, 2019 at 16:33 Juancarlo Añez wrote:

On Wed, Dec 4, 2019 at 3:02 PM Guido van Rossum wrote:

...

Fair enough. I’ll let the OP defend his use case.

The OP thinks that the case for wanting just the string for a first regex match, or a verifiable default if there is no match, is way too common, that the advice on the web is not very good (it should be "write a findfirst() using next() over finditer()", and that novices default to using findall(..)[0], which is troublesome.

The proposed implementation of a findfirst() would handle many common cases, and be friendly to newcomers (why do I need to deal with a Match object?), specially if the semantics are those of *findall()*:

next(iter(findall(...)), default=default)

BTW, a common function in extensions to *itertools* is *first():*

def first(seq, default=None): return next(iter(seq), default= default)

That function, *first()*, would also be a nice addition in *itertools*, and *findfirst()* could be implemented using it. *first()* avoids most use cases needing to check if a sequence or iterator is empty before using a default value. MHO is that *first()* deals with so many common cases that it should be a builtin.

Note that the case for *findfirst()* is weaker if *first()* is available. Yet *findfirst()* solves the bigger problem.

-- Juancarlo *Añez* tel:+58(414)901-2021 skype:juancarloanez

-- --Guido (mobile)