class_docstr: This class represents a process running in a pseudoterminal.
  
  The main constructor is the :meth:`spawn` classmethod.
docstr: Read one line from the pseudoterminal, and return it as unicode.
  
  Can block if there is nothing to read. Raises :exc:`EOFError` if the
  terminal was closed.
docstr_tok: ["Read","one","line","from","the","pseudoterminal",",","and","return","it","as","unicode",".","Can","block","if","there","is","nothing","to","read",".","Raises",":","exc",":","`","EOFError","`","if","the","terminal","was","closed","."]
code: def readline(self):
      """Read one line from the pseudoterminal, and return it as unicode.
  
      Can block if there is nothing to read. Raises :exc:`EOFError` if the
      terminal was closed.
      """
      try:
          s = self.fileobj.readline()
      except (OSError, IOError) as err:
          if err.args[0] == errno.EIO:
              # Linux-style EOF
              self.flag_eof = True
              raise EOFError(
                  "End Of File (EOF). Exception style platform."
              )
          raise
      if s == b"":
          # BSD-style EOF (also appears to work on recent Solaris (OpenIndiana))
          self.flag_eof = True
          raise EOFError(
              "End Of File (EOF). Empty string style platform."
          )
  
      return s
  
imports: import codecs
  import errno
  import fcntl
  import io
  import os
  import pty
  import resource
  import signal
  import struct
  import sys
  import termios
  import time
  from pty import STDIN_FILENO, CHILD
  from .util import which, PtyProcessError
label_desc: Use image node_id 15 for calling the PtyProcess obj's underlying member method code with example usage: obj.readline() and returns: s