title: List being recognized as tuple
body: <p>My code, explains that this is a list. But somehow, the system is giving me a exception:</p>
  
  <pre><code>TypeError: 'tuple' object doesn't support item deletion
  </code></pre>
  
  <p>My code explains this with:</p>
  
  <pre><code>x = (insert a tuple elements here)
  x = list(x)
  </code></pre>
  
  <p>My code is this (I'm progamming a code that will recognize a number expression. This and more in <a href="https://github.com/CaioFrancisco/Mathy" rel="nofollow noreferrer">this lib.</a>)</p>
  
  <pre><code>def num_expression(*nums):
      nums = list(nums)
  
  
      if '*' in nums:
          numsam = nums
          search = __charposition(numsam,'*')
          nums2 = 0
          nums3 = 0
          for i in search:
              num2 = i - 1
              num3 = i + 1
              del numsam[i]
              num4 = numsam[num2]*numsam[num3]
              syn = i - 1
              del numsam[syn]
              numsam[i] = num4
      if '/' in nums:
          numsam = nums
          search = __charposition(numsam,'/')
          nums2 = 0
          nums3 = 0
          for i in search:
              num2 = i - 1
              num3 = i + 1
              del numsam[i]
              num4 = numsam[num2]/numsam[num3]
              syn = i - 1
              del numsam[syn]
              numsam[i] = num4
      excptd_vari = 1
      pos = 0
      num = 0
      syn1 = ''
      syn2 = ''
      syn3 = ''
      syn4 = ''
      size = len(nums)
  
      for i in nums:
  
          if expctd_vari == 1 and isinstance(i, int):
              syn1 = i
              expctd_vari = 2
              num1syn = True
          elif expctd_vari == 2 and isinstance(i, str):
              syn2 = i
              expctd_vari = 3
  
          elif expctd_vari == 3 and isinstance(i, int):
              expctd_vari = 2
              if num1syn == True:
                  syn3 = i
                  if syn2 == '+':
                      num+= syn1+syn3
                  if syn2 == '-':
                      num-= syn1+syn3
                  else:
                      raise SyntaxError
                  num1syn = False
              else:
                  syn4 = i
                  if syn2 == '+':
                      num+= syn3+syn4
                  if syn2 == '-':
                      num-= syn3+syn4
          else:
              raise SyntaxError
  
  def __charposition(string, char):
      pos = [] 
      for n in range(len(string)):
          if string[n] == char:
              pos.append(n)
      return pos
  </code></pre>
  
  <p>Observation: I'm fixing divider problem too. It's just add an return in the final.</p>