class_docstr: Interface to write and read from shared memory. Whereas PlasmaArray writes to plasma on serialization,
  PlasmaView writes to shared memory on instantiation.
class_docstr_tok: ["Interface","to","write","and","read","from","shared","memory",".","Whereas","PlasmaArray","writes","to","plasma","on","serialization",",","PlasmaView","writes","to","shared","memory","on","instantiation","."]
docstr: Save reads by caching len
docstr_tok: ["Save","reads","by","caching","len"]
code: def __len__(self):
      """Save reads by caching len"""
      if self._n is None:
          self._n = len(self.array)
      return self._n
  
imports: import hashlib
  import json
  import subprocess
  import tempfile
  from typing import Hashable
label_desc: Use image node_id 9 for calling the PlasmaView obj's underlying member method code with example usage: obj.__len__() and returns: self