I have two lists of integers:
xList = [(1, 2), (3,4)]
yList = [(5, 6), (7, 8)]
I want to add the first element of xList to the first element of yList etc so that the output is as follows
[(6, 8), (10, 12)]
Any ideas that I can try using numpy or otherwise?
CodePudding user response：
Using a list comprehension:
out = [tuple(map(sum, zip(*x))) for x in zip(xList, yList)]
Output:
[(6, 8), (10, 12)]
generalization
This works independently of the number of input lists. For more lists:
lists = [wList, xList, yList, zList]
out = [tuple(map(sum, zip(*x))) for x in zip(*lists)]
input of uneven size
xList = [(1, 2), (3,4)]
yList = [(5, 6), (7, 8)]
zList = [(1,1)]
from itertools import zip_longest
lists = [xList, yList, zList]
out = [tuple(map(sum, zip(*x)))
for x in zip_longest(*lists, fillvalue=(0,0))]
Output:
[(7, 9), (10, 12)]
CodePudding user response：
For a pure-Python approach you can use operator.add(a, b) (returns a b) from the operator module combined with the built-in functions map(function, iterable, ...) and zip(*iterables, strict=False). The map function "[r]eturn[s] an iterator that applies function to every item of iterable, yielding the results" and the zip function iterates over several iterables in parallel, successively yielding tuples of these elements.
import operator
xList = [(1, 2), (3,4)]
yList = [(5, 6), (7, 8)]
res = [tuple(map(operator.add, a, b)) for a, b in zip(xList, yList)]
print(res)
Output
[(6, 8), (10, 12)]
CodePudding user response：
[(a[0] b[0], a[1] b[1]) for a, b in zip(xList, yList)]
CodePudding user response：
x = np.array(xList)
y = np.array(yList)
print(x y)
Output:
array([[ 6, 8],
[10, 12]])
To make your exact desired output, though I doubt it'll matter:
print([*map(tuple, (x y))])
...
[(6, 8), (10, 12)]
CodePudding user response：
numpy is overkill for this problem. All you need is zip() and a list comprehension:
[(x1 y1, x2 y2) for (x1, x2), (y1, y2) in zip(xList, yList)]
This outputs:
[(6, 8), (10, 12)]