There is a built-in identity function in Python. The function is called 'id'. See https://docs.python.org/3/library/functions.html#id Note that this will not behave the same across different Python runtimes. e.g. CPython, IronPython or Jython all implement this differently.
An example: Python 3.5.2 (default, Sep 14 2017, 22:51:06) [GCC 5.4.0 20160609] on linux Type "help", "copyright", "credits" or "license" for more information. >>> a = 1 >>> b = 2 >>> id(a) 10911168 >>> id(b) 10911200 >>> c = 1 >>> id (c) 10911168 Regards, Nathan On Thu, Dec 7, 2017 at 1:46 PM, Paul Moore <p.f.mo...@gmail.com> wrote: > On 7 December 2017 at 18:28, Ethan Furman <et...@stoneleaf.us> wrote: > > The simple answer is No, and all the answers agree on that point. > > > > It does beg the question of what an identity function is, though. > > > > My contention is that an identity function is a do-nothing function that > > simply returns what it was given: > > > > --> identity(1) > > 1 > > > > --> identity('spam') > > 'spam' > > > > --> identity('spam', 'eggs', 7) > > ('spam', 'eggs', 7) > > > > Of the five answers to that SO question, mine is the only one that will > > correctly handle those three examples. If you agree with my contention > feel > > free to up-vote my answer. :) > > IMO (as a mathematician ;-)) the identity function is a > *single-argument* function that returns the value passed to it. So: > > def identity(x): > return x > > See https://en.wikipedia.org/wiki/Identity_function > > identity(1,2) is an error. > > Extending the definition to multiple arguments causes all sorts of > confusion, as you've seen. > > Paul > -- > https://mail.python.org/mailman/listinfo/python-list > -- https://mail.python.org/mailman/listinfo/python-list