docstr: Send data to the subprocess' stdin.
  
  Returns the number of bytes written.
docstr_tok: ["Send","data","to","the","subprocess","'","stdin",".","Returns","the","number","of","bytes","written","."]
code: def send(self, s):
      """Send data to the subprocess' stdin.
  
      Returns the number of bytes written.
      """
      s = self._coerce_send_string(s)
      self._log(s, "send")
  
      b = self._encoder.encode(s, final=False)
      if PY3:
          return self.proc.stdin.write(b)
      else:
          # On Python 2, .write() returns None, so we return the length of
          # bytes written ourselves. This assumes they all got written.
          self.proc.stdin.write(b)
          return len(b)
  
imports: import os
  import threading
  import subprocess
  import sys
  import time
  import signal
  import shlex
  from .spawnbase import SpawnBase, PY3
  from .exceptions import EOF
  from .utils import string_types
label_desc: Use image node_id 6 for calling the PopenSpawn obj's underlying member method code with example usage: obj.send(s) and returns: self, len