Python'object（）不带参数'错误

Question

I have the class parameter below which should return the index of 2 numbers within the 'nums' list that sums up to the target.

When I tried to test the class using 9 as the target by writing 'Solution(nums,9)', Python returned the 'TypeError: object() takes no parameters' error. Can anyone advise me on what I did wrong in my script?

nums = [2, 7, 11, 15]
class Solution(object):
    def twoSum(self, nums, target):
        nums_1 = nums        
        for i in range(len(nums)):
            for a in range(len(nums_1)):
                if i != a:
                    if nums[i] + nums_1[a] == target:
                        return(sorted([i, a]))
Solution(nums,9)

Traceback (most recent call last):
TypeError: object() takes no parameters

Answer 1

You can't use it like that, because your class have default __init__(which your class get by default, since you didn't define it), and it doesn't take any parameters unless you define it to take it.

Use the following:

sol = Solution()
sorted_stuff = sol.twoSum(nums, 9)
print(sorted_stuff)

Answer 2

You have missed the __init__() method while defining your Solution class. Its not always compulsory, but since you are creating an instance of the class by calling Solution() with some arguments, the __init__ method must be implemented. So the implementation can be:

_nums = [2, 7, 11, 15]
class Solution(object):
    def __init(nums, target):
      self.nums = nums
      self.target = target

    def twoSum(self, nums=None, target=None):
        if not nums:
           nums = self.nums

        if not target:
           target= self.target

        nums_1 = nums        
        for i in range(len(nums)):
            for a in range(len(nums_1)):
                if i != a:
                    if nums[i] + nums_1[a] == target:
                        return(sorted([i, a]))
s = Solution(_nums,9)
s.twoSum()

Also you can do:

 s = Solution()
 s.twoSum(_nums,9)

This gives you the freedom to either have the args defined during the class initialization or calling the actual method with the args.