Python method that sums tuples in a list based on a loop?

Question

I have the following arguments:

a = [(3, 3)]

b = [(2, 0), (1, 0), (0,1), (0,2), (1,1)]

I need to write a function that generates a list of tuples where each element is a unique summation of a and the elements of b. This is my expected result:

c = [(5, 3), (4, 3), (3, 4), (3, 5), (4, 4)]

I am having trouble writing this into a function that will work regardless of what tuple is inputted in a. I can write the code that works on one individual element via the below:

import operator

a = 3, 3
b = 2, 0
result = tuple(map(operator.add, a, b))

How can I turn this into a reproducible function? I have tried several avenues / syntax and believe I am missing something simple.

Answer 1

If a is always a list of a tuple with two elems, the following should work:

def example(a, b):
    toRet = []
    op1, op2 = a[0]
    for val1, val2 in b:
        toRet.append((val1 + op1, val2 + op2))
    return toRet


a = [(3, 3)]
b = [(2, 0), (1, 0), (0, 1), (0, 2), (1, 1)]
c = [(5, 3), (4, 3), (3, 4), (3, 5), (4, 4)]
print(f"Output correct: {example(a, b) == c}")

Output

Output correct: True

Process finished with exit code 0

Answer 2

If a is always guaranteed to be a list of a single tuple you can use this simple list comprehension:

>>> [(a[0][0] + x, a[0][1] + y) for x, y in b]
[(5, 3), (4, 3), (3, 4), (3, 5), (4, 4)]

As a side note, generator expressions and list comprehensions are considered more pythonic when compared to map.