Python cbook.open_file_cm函数代码示例

 def print_png(self, fname_or_fh, *args, **kwargs):
     """Use LaTeX to compile a pgf figure to pdf and convert it to png."""
     if kwargs.get("dryrun", False):
         self._print_pgf_to_fh(None, *args, **kwargs)
         return
     with cbook.open_file_cm(fname_or_fh, "wb") as file:
         self._print_png_to_fh(file, *args, **kwargs)

    def print_svg(self, filename, *args, **kwargs):
        with cbook.open_file_cm(filename, "w", encoding="utf-8") as fh:

            filename = getattr(fh, 'name', '')
            if not isinstance(filename, six.string_types):
                filename = ''

            if cbook.file_requires_unicode(fh):
                detach = False
            else:
                if six.PY3:
                    fh = io.TextIOWrapper(fh, 'utf-8')
                else:
                    fh = codecs.getwriter('utf-8')(fh)
                detach = True

            result = self._print_svg(filename, fh, **kwargs)

            # Detach underlying stream from wrapper so that it remains open in
            # the caller.
            if detach:
                if six.PY3:
                    fh.detach()
                else:
                    fh.reset()
                    fh.stream = io.BytesIO()

        return result

 def print_pdf(self, fname_or_fh, *args, **kwargs):
     """Use LaTeX to compile a Pgf generated figure to PDF."""
     if kwargs.get("dryrun", False):
         self._print_pgf_to_fh(None, *args, **kwargs)
         return
     with cbook.open_file_cm(fname_or_fh, "wb") as file:
         self._print_pdf_to_fh(file, *args, **kwargs)

 def print_pgf(self, fname_or_fh, *args, **kwargs):
     """
     Output pgf commands for drawing the figure so it can be included and
     rendered in latex documents.
     """
     if kwargs.get("dryrun", False):
         self._print_pgf_to_fh(None, *args, **kwargs)
         return
     with cbook.open_file_cm(fname_or_fh, "w", encoding="utf-8") as file:
         if not cbook.file_requires_unicode(file):
             file = codecs.getwriter("utf-8")(file)
         self._print_pgf_to_fh(file, *args, **kwargs)

    def print_png(self, filename_or_obj, *args, **kwargs):
        FigureCanvasAgg.draw(self)
        renderer = self.get_renderer()

        version_str = (
            'matplotlib version ' + __version__ + ', http://matplotlib.org/')
        metadata = OrderedDict({'Software': version_str})
        user_metadata = kwargs.pop("metadata", None)
        if user_metadata is not None:
            metadata.update(user_metadata)

        with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \
                cbook.open_file_cm(filename_or_obj, "wb") as fh:
            _png.write_png(renderer._renderer, fh,
                            self.figure.dpi, metadata=metadata)

    def print_png(self, filename_or_obj, *args, **kwargs):
        FigureCanvasAgg.draw(self)
        renderer = self.get_renderer()
        original_dpi = renderer.dpi
        renderer.dpi = self.figure.dpi

        version_str = 'matplotlib version ' + __version__ + \
            ', http://matplotlib.org/'
        metadata = OrderedDict({'Software': version_str})
        user_metadata = kwargs.pop("metadata", None)
        if user_metadata is not None:
            metadata.update(user_metadata)

        try:
            with cbook.open_file_cm(filename_or_obj, "wb") as fh:
                _png.write_png(renderer._renderer, fh,
                               self.figure.dpi, metadata=metadata)
        finally:
            renderer.dpi = original_dpi

 def print_svgz(self, filename, *args, **kwargs):
     with cbook.open_file_cm(filename, "wb") as fh, \
             gzip.GzipFile(mode='w', fileobj=fh) as gzipwriter:
         return self.print_svg(gzipwriter)

    def print_png(self, filename_or_obj, *args,
                  metadata=None, pil_kwargs=None,
                  **kwargs):
        """
        Write the figure to a PNG file.

        Parameters
        ----------
        filename_or_obj : str or PathLike or file-like object
            The file to write to.

        metadata : dict, optional
            Metadata in the PNG file as key-value pairs of bytes or latin-1
            encodable strings.
            According to the PNG specification, keys must be shorter than 79
            chars.

            The `PNG specification`_ defines some common keywords that may be
            used as appropriate:

            - Title: Short (one line) title or caption for image.
            - Author: Name of image's creator.
            - Description: Description of image (possibly long).
            - Copyright: Copyright notice.
            - Creation Time: Time of original image creation
              (usually RFC 1123 format).
            - Software: Software used to create the image.
            - Disclaimer: Legal disclaimer.
            - Warning: Warning of nature of content.
            - Source: Device used to create the image.
            - Comment: Miscellaneous comment;
              conversion from other image format.

            Other keywords may be invented for other purposes.

            If 'Software' is not given, an autogenerated value for matplotlib
            will be used.

            For more details see the `PNG specification`_.

            .. _PNG specification: \
                https://www.w3.org/TR/2003/REC-PNG-20031110/#11keywords

        pil_kwargs : dict, optional
            If set to a non-None value, use Pillow to save the figure instead
            of Matplotlib's builtin PNG support, and pass these keyword
            arguments to `PIL.Image.save`.

            If the 'pnginfo' key is present, it completely overrides
            *metadata*, including the default 'Software' key.
        """
        from matplotlib import _png

        if metadata is None:
            metadata = {}
        metadata = {
            "Software":
                f"matplotlib version{__version__}, http://matplotlib.org/",
            **metadata,
        }

        if pil_kwargs is not None:
            from PIL import Image
            from PIL.PngImagePlugin import PngInfo
            buf, size = self.print_to_buffer()
            # Only use the metadata kwarg if pnginfo is not set, because the
            # semantics of duplicate keys in pnginfo is unclear.
            if "pnginfo" not in pil_kwargs:
                pnginfo = PngInfo()
                for k, v in metadata.items():
                    pnginfo.add_text(k, v)
                pil_kwargs["pnginfo"] = pnginfo
            pil_kwargs.setdefault("dpi", (self.figure.dpi, self.figure.dpi))
            (Image.frombuffer("RGBA", size, buf, "raw", "RGBA", 0, 1)
             .save(filename_or_obj, format="png", **pil_kwargs))

        else:
            FigureCanvasAgg.draw(self)
            renderer = self.get_renderer()
            with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \
                    cbook.open_file_cm(filename_or_obj, "wb") as fh:
                _png.write_png(renderer._renderer, fh,
                               self.figure.dpi, metadata=metadata)