Code for reproducing the Benchmarks of https://stackoverflow.com/a/69812299/4001592

nested_find.py

from operator import eq
from functools import partial
import perfplot
import random


def nested_list_comprehension(names, needle="Matt"):
    return [[name for name in lst if needle == name] for lst in names]


def functional_approach(names, needle="Matt"):
    eq_matt = partial(eq, needle)
    return [[*filter(eq_matt, lst)] for lst in names]


def count_approach(names, needle="Matt"):
    return [[needle] * name.count(needle) for name in names]


def setup(length):
    population = ["Matt", "James", "William", "Charles", "Paul", "John", "JJ", "Peter", "George", "Edward", "Harry",
                  "Ronald", "Boris", "Donald"]
    return [random.choices(population, k=10) for _ in range(length)]


def equality_check(a, b):
    return a == b


if __name__ == "__main__":
    b = perfplot.bench(
        setup=setup,
        kernels=[
            nested_list_comprehension,
            functional_approach,
            count_approach
        ],
        labels=["nested_list_comp", "functional", "count"],
        n_range=[k for k in range(100, 1001, 100)],
        xlabel="len(a)",
        equality_check=equality_check
    )

    b.save("out.png")
    b.show()