Method _write_metadata

lib/matplotlib/backends/backend_svg.py:363–484

(self, metadata)

        self.writer.flush()

    def _write_metadata(self, metadata):
        # Add metadata following the Dublin Core Metadata Initiative, and the
        # Creative Commons Rights Expression Language. This is mainly for
        # compatibility with Inkscape.
        if metadata is None:
            metadata = {}
        metadata = {
            'Format': 'image/svg+xml',
            'Type': 'http://purl.org/dc/dcmitype/StillImage',
            'Creator':
                f'Matplotlib v{mpl.__version__}, https://matplotlib.org/',
            **metadata
        }
        writer = self.writer

        if 'Title' in metadata:
            title = metadata['Title']
            _check_is_str(title, 'Title')
            writer.element('title', text=title)

        # Special handling.
        date = metadata.get('Date', None)
        if date is not None:
            if isinstance(date, str):
                dates = [date]
            elif isinstance(date, (datetime.datetime, datetime.date)):
                dates = [date.isoformat()]
            elif np.iterable(date):
                dates = []
                for d in date:
                    if isinstance(d, str):
                        dates.append(d)
                    elif isinstance(d, (datetime.datetime, datetime.date)):
                        dates.append(d.isoformat())
                    else:
                        raise TypeError(
                            f'Invalid type for Date metadata. '
                            f'Expected iterable of str, date, or datetime, '
                            f'not {type(d)}.')
            else:
                raise TypeError(f'Invalid type for Date metadata. '
                                f'Expected str, date, datetime, or iterable '
                                f'of the same, not {type(date)}.')
            metadata['Date'] = '/'.join(dates)
        elif 'Date' not in metadata:
            # Do not add `Date` if the user explicitly set `Date` to `None`
            # Get source date from SOURCE_DATE_EPOCH, if set.
            # See https://reproducible-builds.org/specs/source-date-epoch/
            date = os.getenv("SOURCE_DATE_EPOCH")
            if date:
                date = datetime.datetime.fromtimestamp(int(date), datetime.timezone.utc)
                metadata['Date'] = date.replace(tzinfo=UTC).isoformat()
            else:
                metadata['Date'] = datetime.datetime.today().isoformat()

        mid = None
        def ensure_metadata(mid):
            if mid is not None: