proper name for python * operator?

233
votes

What is the correct name for operator *, as in function(*args)? unpack, unzip, something else?

9
pythonoperatorssplat
Javascript has the equivalent spread ... operator. - Wolfgang Kuehn
Just for reference, in the C++, it is called Dereference Operator (ref: cplusplus.com/doc/tutorial/pointers). Additionally, in Python, all variable to function (arguments) is pass by assignment. (ref: docs.python.org/3/faq/…) - Cloud Cho
@CloudCho The one in C++ stands for something entirely different. - Sнаđошƒаӽ
@Sнаđошƒаӽ Would you describe the difference between Dereference Operator (C++) and Unpacking Operator (Python)? I thought both of them related to memory location rather than value in memory. Thanks. - Cloud Cho
@CloudCho Take a look at the official documentation. - Sнаđошƒаӽ

9 Answers

197
votes

In Ruby and Perl 6 this has been called "splat", and I think most people from those communities will figure out what you mean if you call it that.

The Python tutorial uses the phrase "unpacking argument lists", which is long and descriptive.

It is also referred to as iterable unpacking, or in the case of **, dictionary unpacking.

122
votes

I call it "positional expansion", as opposed to ** which I call "keyword expansion".

51
votes

The Python Tutorial simply calls it 'the *-operator'. It performs unpacking of arbitrary argument lists.

17
votes

I say "star-args" and Python people seem to know what i mean.

** is trickier - I think just "qargs" since it is usually used as **kw or **kwargs

13
votes

One can also call * a gather parameter (when used in function arguments definition) or a scatter operator (when used at function invocation).

As seen here: Think Python/Tuples/Variable-length argument tuples.

6
votes

I believe it's most commonly called the "splat operator." Unpacking arguments is what it does.

2
votes

The technical term for this is a Variadic function. So in a sense, that's the correct term without regard to programming language.

That said, in different languages the term does have legitimate names. As others have mentioned, it is called "splat" in ruby, julia, and several other languages and is noted by that name in official documentation. In javascript it is called the "spread" syntax. It has many other names in many other languages, as mentioned in other answers. Whatever you call it, it's quite useful!

0
votes

I call *args "star args" or "varargs" and **kwargs "keyword args".

-1
votes

For a colloquial name there is "splatting".

For arguments (list type) you use single * and for keyword arguments (dictionary type) you use double **.

Both * and ** is sometimes referred to as "splatting".

See for reference of this name being used: https://stackoverflow.com/a/47875892/14305096