Elementwise operations over tuples in Python

Question

Are there any built-in functions that allow elementwise operations over tuples in Python 3? If not, what is the "pythonic" way to perform these operations?

Example: I want to take the percent difference between a and b and compare them to some threshold th.

>>> a = (1, 2, 4)
>>> b = (1.1, 2.1, 4.1)
>>> # compute pd = 100*abs(a-b)/a = (10.0, 5.0, 2.5)
>>> th = 3
>>> # test threshold: pd < th => (False, False, True)

Answer 1

There is no builtin way, but there is a pretty simple way:

[f(aItem, bItem) for aItem, bItem in zip(a, b)]

. . . where f is the function you want to apply elementwise. For your case:

[100*abs(aItem - bItem)/aItem < 3 for aItem, bItem in zip(a, b)]

If you find yourself doing this a lot, especially with long tuples, you might want to look at Numpy, which provides a full-featured system of vector operations in which many common vector functions (basic operations, trig functions, etc.) apply elementwise.