What does the slash mean in help() output?

Question

What does the / mean in Python 3.4\'s help output for range before the closing parenthesis?

>>> help(range)
H         


        

Answer 1

I asked this question myself. :) Found out that / was originally proposed by Guido in here.

Alternative proposal: how about using '/' ? It's kind of the opposite of '*' which means "keyword argument", and '/' is not a new character.

Then his proposal won.

Heh. If that's true, my '/' proposal wins:

 def foo(pos_only, /, pos_or_kw, *, kw_only): ...

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I think the very relevant document covering this is PEP 570. Where recap section looks nice.

Recap

The use case will determine which parameters to use in the function definition:

 def f(pos1, pos2, /, pos_or_kwd, *, kwd1, kwd2):

As guidance:

Use positional-only if names do not matter or have no meaning, and there are only a few arguments which will always be passed in the same order. Use keyword-only when names have meaning and the function definition is more understandable by being explicit with names.

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If the function ends with /

def foo(p1, p2, /)

This means all functional arguments are positional.