Source code for filewriter

#!/usr/bin/env python
"""
.. module:: filewriter.py
   :platform: Unix, Windows
   :synopsis: Ulyxes - an open source project to drive total stations and
       publish observation results.
       GPL v2.0 license
       Copyright (C) 2010- Zoltan Siki <siki.zoltan@epito.bme.hu>

.. moduleauthor:: Zoltan Siki <siki.zoltan@epito.bme.hu>
"""

import sys
import logging
from angle import Angle
from writer import Writer

class FileWriter(Writer):
    """ Class to write observations to file, in the form key=value;key=value,...

            :param name: name of writer (str), default None
            :param angle: angle unit to use (str), default GON
            :param dist: distance and coordinate format (str), default 3 decimals
            :param dt: date/time format (str), default ansi
            :param filt: list of allowed keys (list), default None
            :param fname: name of text file to write to (str), default None (write to stdout)
            :param mode: mode of file open (a or w) (str)
    """

    def __init__(self, name='None', angle='GON', dist='.3f',
                 dt='%Y-%m-%d %H:%M:%S', filt=None, fname=None,
                 mode='a'):
        """ Constructor
        """
        super().__init__(name, angle, dist, dt, filt)
        self.fname = fname
        self.mode = mode
        self.fp = None
        if fname is None or fname == 'stdout':
            # write to stdout
            self.fp = sys.stdout
        else:
            try:
                self.fp = open(fname, mode)
            except Exception:
                self.state = self.WR_OPEN
                logging.error(" cannot open file %s", self.fname)

    def __del__(self):
        """ Destructor
        """
        try:
            self.fp.close()
        except Exception:
            pass

    def WriteData(self, data):
        """ Write observation data to file

            :param data: dictionary with observation data
        """
        line = ""
        if data is None or self.DropData(data):
            logging.warning(" empty or inappropiate data not written")
            return -2
        # add datetime and/or id
        data = self.ExtendData(data)
        for key, val in data.items():
            if self.filt is None or key in self.filt:
                line += key + "=" + self.StrVal(val) + ";"
        try:
            self.fp.write(line + "\n")
            self.fp.flush()
        except Exception:
            logging.error(" file write failed")
            return -1
        return 0

if __name__ == "__main__":
    myfile = FileWriter()   # write to stdout
    data = {'hz': Angle(0.12345), 'v': Angle(100.2365, 'GON'), 'dist': 123.6581}
    myfile.WriteData(data)