The problematic `findall(...)[0]` is a common anti-pattern in Python programs. The reason is lack of symmetry and completeness in the `re` module.

The original proposal in `python-ideas` was to add `re.findfirst(pattern, string, flags=0, default=_mark)` with more or less the semantics of `next(findall(pattern, string, flags=flags), default=default)`. 

The referenced PR adds `findalliter(pattern, string, flags=0)` with the value semantics of `findall()` over a generator, implements `findall()` as `return list(findalliter(...))`, and implements `findfirst()`. 

Consistency and correctness are likely because all tests pass with the redefined `findall()`.