class SerialException(Exception): pass class FileLike: """An abstract file like class. This class implements readline and readlines based on read and writelines based on write. This class is used to provide the above functions for to Serial port objects. Note that when the serial port was opened with _NO_ timeout that readline blocks until it sees a newline (or the specified size is reached) and that readlines would never return and therefore refuses to work (it raises an exception in this case)! """ def read(self, size): raise NotImplementedError def write(self, s): raise NotImplementedError def readline(self, size=None, eol='\n'): """read a line which is terminated with end-of-line (eol) character ('\n' by default) or until timeout""" line = '' while 1: c = self.read(1) if c: line += c #not very efficient but lines are usually not that long if c == eol: break if size is not None and len(line) >= size: break else: break return line def readlines(self, sizehint=None, eol='\n'): """read a list of lines, until timeout sizehint is ignored""" if self.timeout is None: raise ValueError, "Serial port MUST have enabled timeout for this function!" lines = [] while 1: line = self.readline(eol=eol) if line: lines.append(line) if line[-1] != eol: #was the line received with a timeout? break else: break return lines def xreadlines(self, sizehint=None): """just call readlines - here for compatibility""" return self.readlines() def writelines(self, sequence): for line in sequence: self.write(line) def flush(self): """flush of file like objects""" pass