code: def cvt_iter(a):
      '''
      Convert an iterator/generator to a tuple so that it can be iterated again.
  
      E.g., convert zip in PY3.
      '''
      if a is None:
          return a
  
      if not isinstance(a, (tuple, list)):
          # convert iterator/generator to tuple
          a = tuple(a)
      return f cvt_iter(a):
      '''
      Convert an iterator/generator to a tuple so that it can be iterated again.
  
      E.g., convert zip in PY3.
      '''
      if a is None:
          return a
  
      if not isinstance(a, (tuple, list)):
          # convert iterator/generator to tuple
          a = tuple(a)
      return a
docs: Convert an iterator/generator to a tuple so that it can be iterated again.
  
      E.g., convert zip in PY3.