列表2>sum13编码bat问题：“int”对象不可编辑

Question

我的代码有问题。问题是:

返回数组中数字的总和，空数组返回0。除此之外，数字13是非常不吉利的，所以它不算数，紧跟在13之后的数字也不算数。 发件人：https://codingbat.com/prob/p167025

def sum13(nums):
  if not nums:
    return 0
  for x in nums:
    if x == 13:
      break
    return sum(x)
    if 13 not in nums:
      return sums(nums)

问题是我不能合并和（x），每次尝试时它都会给出一个错误。 有人能暗示一下原因吗

Answer 1

错位return是这里的许多问题之一，但可能是修复逻辑的良好开端。很难找出一个问题，一旦解决，将产生预期的结果。相反，存在一个普遍的问题，即实现与任务逻辑无关

通常，您会将问题分解为更简单的砖块，有点像这样：

def sum13(nums):
    # "Return the sum of the numbers in the array" 
    #  - let's iterate the array, increasing the sum
    res = 0
    previous_is_13 = False  # introduced later

    # "returning 0 for an empty array."
    # for loop will do nothing on empty arrays, as desired
    for i in nums:  
        # "Except the number 13 is very unlucky, so it does not count"
        # so, let's guard it with an if:
        if i == 13:
            # "numbers that come immediately after a 13 also do not count."
            # ok, let's set a flag to indicate that and clear it once we're past 13
            previous_is_13 = True
            continue

        if previous_is_13:
            previous_is_13 = False  # clear the flag and proceed to the next item
            continue
        res += i
    return res

一旦您有了基线解决方案，就要使它变得更好，例如使用迭代器：

def sum13(nums):
    return sum(value for i, value in enumerate(nums)
               if value!= 13 and (not i or nums[i-1] != 13))