How do I call a function twice or more times consecutively?

Question

Is there a short way to call a function twice or more consecutively in Python? For example:

do()
do()
do()

maybe like:

3*do         


        

Answer 1

Here is an approach that doesn't require the use of a for loop or defining an intermediate function or lambda function (and is also a one-liner). The method combines the following two ideas:

• calling the iter() built-in function with the optional sentinel argument, and

• using the itertools recipe for advancing an iterator n steps (see the recipe for consume()).

Putting these together, we get:

next(islice(iter(do, object()), 3, 3), None)

(The idea to pass object() as the sentinel comes from this accepted Stack Overflow answer.)

And here is what this looks like from the interactive prompt:

>>> def do():
...   print("called")
... 
>>> next(itertools.islice(iter(do, object()), 3, 3), None)
called
called
called