from basic_function_helper import do_square_using_c

...

my_list = np.arange(1000)

squared_list = do_square_using_c(*my_list)

def do_square_using_c(list_in):

"""Call C function to calculate squares"""

n = len(list_in)

c_arr_in = (c_double * n)(*list_in)

c_arr_out = (c_double * n)()

python_c_square(c_int(n), c_arr_in, c_arr_out)

return c_arr_out[:]