Benchmarking https://stackoverflow.com/a/56844986/554436

test.py

# https://stackoverflow.com/a/56844986/554436

def test(s):
    d = {"foo": "foo", "bar": "bar"}
    return d.get(s)

if __name__ == '__main__':
    from dis import dis
    from timeit import timeit

    code_1 = '"foo" in {test("foo"), test("tar")}'
    code_2 = '"foo" == test("foo") or "foo" == test("tar")'

    print('--------')
    print(code_1)
    print(dis(code_1))
    print(code_2)
    print(dis(code_2))
    print('--------')
    print(code_1)
    print(timeit(code_1, setup="from __main__ import test"))
    print(code_2)
    print(timeit(code_2, setup="from __main__ import test"))

# OUTPUT:
# --------
# "foo" in {test("foo"), test("tar")}
#   1           0 LOAD_CONST               0 ('foo')
#               2 LOAD_NAME                0 (test)
#               4 LOAD_CONST               0 ('foo')
#               6 CALL_FUNCTION            1
#               8 LOAD_NAME                0 (test)
#              10 LOAD_CONST               1 ('tar')
#              12 CALL_FUNCTION            1
#              14 BUILD_SET                2
#              16 COMPARE_OP               6 (in)
#              18 RETURN_VALUE
# None
# "foo" == test("foo") or "foo" == test("tar")
#   1           0 LOAD_CONST               0 ('foo')
#               2 LOAD_NAME                0 (test)
#               4 LOAD_CONST               0 ('foo')
#               6 CALL_FUNCTION            1
#               8 COMPARE_OP               2 (==)
#              10 JUMP_IF_TRUE_OR_POP     22
#              12 LOAD_CONST               0 ('foo')
#              14 LOAD_NAME                0 (test)
#              16 LOAD_CONST               1 ('tar')
#              18 CALL_FUNCTION            1
#              20 COMPARE_OP               2 (==)
#         >>   22 RETURN_VALUE
# None
# --------
# "foo" in {test("foo"), test("tar")}
# 0.5012693479948211
# "foo" == test("foo") or "foo" == test("tar")
# 0.25610274499922525