code: def isalive (self):
          '''This checks if the file descriptor is still valid. If :func:`os.fstat`
          does not raise an exception then we assume it is alive. '''
  
          if self.child_fd == -1:
              return False
          try:
              os.fstat(self.child_fd)
              return True
          except:
              return Falsf isalive (self):
          '''This checks if the file descriptor is still valid. If :func:`os.fstat`
          does not raise an exception then we assume it is alive. '''
  
          if self.child_fd == -1:
              return False
          try:
              os.fstat(self.child_fd)
              return True
          except:
              return False
docs: This checks if the file descriptor is still valid. If :func:`os.fstat`
          does not raise an exception then we assume it is alive.