how is the readline set_completer function suppose to work

[Peter Otten]

sinbad.sinbad at gmail.com wrote:

> Below i was expecting the test() function to be called, but it doesn't. Am
> i doing it wrong? By the way i'm running version 2.7.10 on a mac.
> 
> $python
> 
>>>> import readline
>>>> def test():
> ...   print("test")
> ...
>>>> test()
> test
>>>> print(help(readline))
> 
> None
>>>> readline.set_completer(test)
>>>> raw_input()
> 
> '\t\t\t'
>>>>

You need to tell readline that you want the tab key to complete with 
parse_and_bind(), and you need a complete function with the right signature:

>>> import readline
>>> def test(prefix, index):
...     try: return [s for s in "foo forge fun".split() if s.startswith(prefix)][index]
...     except IndexError: return None
... 
>>> readline.set_completer(test)
>>> readline.parse_and_bind("tab: complete")
>>> raw_input()
f
foo    forge  fun    
fo
foo    forge  
forge
'forge'