CODEWITHSUNDEEP
python
ramailo sathi
ramailo sathi

Reputation: 355

Solving Two sum: NoneType' is not iterable

The problem statement : Given an array of integers, return indices of the two numbers such that they add up to a specific target.

You may assume that each input would have exactly one solution, and you may not use the same element twice.

My solution(trying to do better than bruteforce approach):

def twoSum(nums, target):
    """
    :type nums: List[int]
    :type target: int
    :rtype: List[int]
    """
    for i in range(0,len(nums)):
        if (target - nums[i]) in nums.remove(nums[i]):  #error
            if i != nums.index(target - nums[i]):
                return i, nums.index(target - nums[i])

I keep getting Line 9: TypeError: argument of type 'NoneType' is not iterable .

I believe.remove() returns a list and I am trying to check if target - nums[i] is in the list.

Upvotes: 0

Views: 113

Answers (2)

Pythonista
Pythonista

Reputation: 11645

a.remove() doesn't return a list. It returns None

>>> a_list = [1, 2]
>>> print(a_list.remove(1))
None
>>> print(a_list)
>>> [2]

As the error message suggest to iterate an object you need an object which is iterable.

Upvotes: 0

Darkstarone
Darkstarone

Reputation: 4730

remove() returns None. Try this instead:

def twoSum(nums, target):
    """
    :type nums: List[int]
    :type target: int
    :rtype: List[int]
    """
    for i in range(0,len(nums)):
        nums.remove(nums[i])
        if (target - nums[i]) in nums:
            if i != nums.index(target - nums[i]):
                return i, nums.index(target - nums[i])

Alternately, if you need to maintain nums, make a copy and remove:

def twoSum(nums, target):
    """
    :type nums: List[int]
    :type target: int
    :rtype: List[int]
    """
    for i in range(0,len(nums)):
        nums_copy = list(nums)
        nums_copy.remove(nums[i])
        if (target - nums[i]) in nums_copy:
            if i != nums.index(target - nums[i]):
                return i, nums.index(target - nums[i])

Upvotes: 1

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