parameters: (self, size=None, eol=LF)
return_statement: return bytes(line)
docstring: read a line which is terminated with end-of-line (eol) character
          ('\n' by default) or until timeout.
docstring_summary: read a line which is terminated with end-of-line (eol) character
          ('\n' by default) or until timeout.
docstring_tokens: read a line which is terminated with end - of - line ( eol ) character ( \ n by default ) or until timeout .
function: def readline(self, size=None, eol=LF):
          """read a line which is terminated with end-of-line (eol) character
          ('\n' by default) or until timeout."""
          leneol = len(eol)
          line = bytearray()
          while True:
              c = self.read(1)
              if c:
                  line += c
                  if line[-leneol:] == eol:
                      break
                  if size is not None and len(line) >= size:
                      break
              else:
                  break
          return bytes(line)
function_tokens: def readline ( self , size = None , eol = LF ) : leneol = len ( eol ) line = bytearray ( ) while True : c = self . read ( 1 ) if c : line += c if line [ - leneol : ] == eol : break if size is not None and len ( line ) >= size : break else : break return bytes ( line )