I am trying to customize my own class for iteration, and tries to plug it into the calculations:
class Iteration:
def __init__(self, array):
self.array = array
def __pow__(self, power, modulo=None):
new_array = list()
for i in self.array:
new_array.append(i ** power)
return new_array
def __len__(self):
return len(self.array)
def __getitem__(self, indices):
return self.array[indices]
def mul(x):
return x ** 2 + 3 * x ** 3
it = Iteration([1, 2, 3])
print(mul(2)) #=> 28
print(mul(it)) #=> [1, 4, 9, 1, 8, 27, 1, 8, 27, 1, 8, 27]
why mul(it) has combined overloaded result? How can I solve this? I want: print(mul(it)) #=> [4, 28, 90]
Your __pow__ returns a list, not an Iteration instance. The + and * operations are list operations, and lists implement + and * as concatenation and repetition.
[1, 4, 9] + 3 * [1, 8, 27] repeats [1, 8, 27] 3 times to get [1, 8, 27, 1, 8, 27, 1, 8, 27], then concatenates [1, 4, 9] and [1, 8, 27, 1, 8, 27, 1, 8, 27].
You need to return an Iteration instance from __pow__, and you need to implement __add__ and __mul__ too, not just __pow__. While you're at it, you might also want to implement __str__ or __repr__, so you can see the data your Iteration object is wrapping when you print it.