On 23/03/2020 14:50, Dan Stromberg wrote:
On Fri, Mar 20, 2020 at 3:28 PM Victor Stinner <vstin...@python.org> wrote:The builtin ``str`` class will gain two new methods with roughly the following behavior:: def cutprefix(self: str, pre: str, /) -> str: if self.startswith(pre): return self[len(pre):] return self[:]I tend to be mistrustful of code that tries to guess the best thing to do, when something expected isn't found. How about: def cutprefix(self: str, pre: str, raise_on_no_match: bool=False, /) -> str: if self.startswith(pre): return self[len(pre):] if raise_on_no_match: raise ValueError('prefix not found') return self[:]
I'm firmly of the opinion that the functions should either raise or not, and should definitely not have a parameter to switch behaviours. Probably it should do nothing; if the programmer needs to know that the prefix wasn't there, cutprefix() probably wasn't the right thing to use anyway.
-- Rhodri James *-* Kynesim Ltd _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-le...@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/SA5RZNAJESODSMNGBX7OD2F77YMHWH5Z/ Code of Conduct: http://python.org/psf/codeofconduct/
