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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def write(self, sync=1):
 """ Write the .sconsign file to disk. Try to write to a temporary file first, and rename it if we succeed. If we can't write to the temporary file, it's probably because the directory isn't writable (and if so, how did we build anything in this directory, anyway?), so try to write directly to the .sconsign file as a backup. If we can't rename, try to copy the temporary contents back to the .sconsign file. Either way, always try to remove the temporary file at the end. """

        if not self.dirty:
            return

        self.merge()

        temp = os.path.join(self.dir.get_internal_path(), '.scons%d' % os.getpid())
        try:
            file = open(temp, 'wb')
            fname = temp
        except IOError:
            try:
                file = open(self.sconsign, 'wb')
                fname = self.sconsign
            except IOError:
                return
        for key, entry in self.entries.items():
            entry.convert_to_sconsign()
        pickle.dump(self.entries, file, PICKLE_PROTOCOL)
        file.close()
        if fname != self.sconsign:
            try:
                mode = os.stat(self.sconsign)[0]
                os.chmod(self.sconsign, 0o666)
                os.unlink(self.sconsign)
            except (IOError, OSError):
                # Try to carry on in the face of either OSError
                # (things like permission issues) or IOError (disk
                # or network issues).  If there's a really dangerous
                # issue, it should get re-raised by the calls below.
                pass
            try:
                os.rename(fname, self.sconsign)
            except OSError:
                # An OSError failure to rename may indicate something
                # like the directory has no write permission, but
                # the .sconsign file itself might still be writable,
                # so try writing on top of it directly.  An IOError
                # here, or in any of the following calls, would get
                # raised, indicating something like a potentially
                # serious disk or network issue.
                open(self.sconsign, 'wb').write(open(fname, 'rb').read())
                os.chmod(self.sconsign, mode)
        try:
            os.unlink(temp)
        except (IOError, OSError):
            pass