Python - is there a way to store an operation(+ - * /) in a list or as a variable?

Question

The reason I ask is pure curiosity. I could see, possibly, that this might be useful if you didn't know ahead of time what operations you wanted to apply to certain variables, or to apply a different operation during a certain level in a recursive call, or perhaps it may just make certain things easier and/or neater.

Though am just speculating, it could be a really bad idea, but overall am just curious.

Check out [`operator`](https://docs.python.org/2/library/operator.html#module-operator) module. — Łukasz Rogalski, May 10 '16 at 15:27

score 12 · Accepted Answer · answered May 10 '16 at 15:29

12

You may use operator module.

The operator module exports a set of efficient functions corresponding to the intrinsic operators of Python. For example, operator.add(x, y) is equivalent to the expression x+y. The function names are those used for special class methods; variants without leading and trailing __ are also provided for convenience.

So storing "operation" in list is as simple as:

import operator
operations = [operator.add, operator.sub]
# add two numbers
s = operations[0](1, 2)

answered May 10 '16 at 15:29

Łukasz Rogalski

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Yeah that pretty much nails it :) – Jim Jam May 10 '16 at 15:30
And if an operator you want isn't in the module, just wrap it in a function; named or otherwise. – Carcigenicate May 10 '16 at 15:30

score 0 · Answer 2 · answered May 10 '16 at 15:28

0

Yes you can put functions in a list, or a dict (which can be quite useful), you can do it with functions declared with def, lambdas or import already defined functions, from operators module with your examples (operator.add, etc)

answered May 10 '16 at 15:28

polku

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Python - is there a way to store an operation(+ - * /) in a list or as a variable?

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