class_docstr: Base Class for series
code: def __getitem__(self, index):
      if isinstance(index, int):
          index = self._ith_point(index)
          return self.term(index)
      elif isinstance(index, slice):
          start, stop = index.start, index.stop
          if start is None:
              start = 0
          if stop is None:
              stop = self.length
          return [
              self.term(self._ith_point(i))
              for i in range(start, stop, index.step or 1)
          ]
  
file_path: sympy/sympy/series/series_class.py
imports: from sympy.core.expr import Expr
  from sympy.core.singleton import S
  from sympy.core.cache import cacheit
label_desc: Use image node_id 11 for calling the SeriesBase obj's underlying member method code with example usage: obj.__getitem__(index) and returns: self, unknown