# Author: Óscar Nájera
# License: 3-clause BSD
"""Scrapers for embedding images.
Collect images that have been produced by code blocks.
The only scraper we natively support is Matplotlib, others should
live in modules that will support them (e.g., PyVista, Plotly). Scraped
images are injected as rst ``image-sg`` directives into the ``.rst``
file generated for each example script.
"""
import importlib
import inspect
import os
import re
import sys
from pathlib import PurePosixPath
from textwrap import indent
from warnings import filterwarnings
from sphinx.errors import ExtensionError
from .utils import optipng
__all__ = [
"save_figures",
"figure_rst",
"ImagePathIterator",
"clean_modules",
"matplotlib_scraper",
]
###############################################################################
# Scrapers
def _import_matplotlib():
"""Import matplotlib safely."""
# make sure that the Agg backend is set before importing any
# matplotlib
import matplotlib
matplotlib.use("agg")
matplotlib_backend = matplotlib.get_backend().lower()
filterwarnings(
"ignore",
category=UserWarning,
message="Matplotlib is currently using agg, which is a"
" non-GUI backend, so cannot show the figure."
"|(\n|.)*is non-interactive, and thus cannot be"
" shown",
)
if matplotlib_backend != "agg":
raise ExtensionError(
"Sphinx-Gallery relies on the matplotlib 'agg' backend to "
"render figures and write them to files. You are "
"currently using the {} backend. Sphinx-Gallery will "
"terminate the build now, because changing backends is "
"not well supported by matplotlib. We advise you to move "
"sphinx_gallery imports before any matplotlib-dependent "
"import. Moving sphinx_gallery imports at the top of "
"your conf.py file should fix this issue".format(matplotlib_backend)
)
import matplotlib.pyplot as plt
return matplotlib, plt
def _matplotlib_fig_titles(fig):
titles = []
# get supertitle if exists
suptitle = getattr(fig, "_suptitle", None)
if suptitle is not None:
titles.append(suptitle.get_text())
# get titles from all axes, for all locs
title_locs = ["left", "center", "right"]
for ax in fig.axes:
for loc in title_locs:
text = ax.get_title(loc=loc)
if text:
titles.append(text)
fig_titles = ", ".join(titles)
return fig_titles
_ANIMATION_RST = """
.. container:: sphx-glr-animation
.. raw:: html
{0}
"""
_ANIMATION_VIDEO_RST = """
.. video:: {video}
:class: sphx-glr-single-img
:height: {height}
:width: {width}
{options}
"""
[docs]
def matplotlib_scraper(block, block_vars, gallery_conf, **kwargs):
"""Scrape Matplotlib images.
Parameters
----------
block : sphinx_gallery.py_source_parser.Block
The code block to be executed. Format (label, content, lineno).
block_vars : dict
Dict of block variables.
gallery_conf : dict
Contains the configuration of Sphinx-Gallery
**kwargs : dict
Additional keyword arguments to pass to
:meth:`~matplotlib.figure.Figure.savefig`, e.g. ``format='svg'``. The
``format`` keyword argument in particular is used to set the file
extension of the output file (currently only 'png', 'jpg', 'svg',
'gif', and 'webp' are supported).
This is not used internally, but intended for use when overriding the scraper.
Returns
-------
rst : str
The reStructuredText that will be rendered to HTML containing
the images. This is often produced by :func:`figure_rst`.
"""
# Do not use _import_matplotlib() to avoid potentially changing the backend
import matplotlib
import matplotlib.pyplot as plt
from matplotlib.animation import Animation
image_path_iterator = block_vars["image_path_iterator"]
image_rsts = []
srcset = gallery_conf["image_srcset"]
# Check for animations
anims = {}
if gallery_conf["matplotlib_animations"][0]:
for ani in block_vars["example_globals"].values():
if isinstance(ani, Animation):
anims[ani._fig] = ani
# Then standard images
for fig_num, image_path in zip(plt.get_fignums(), image_path_iterator):
image_path = PurePosixPath(image_path)
if "format" in kwargs:
image_path = image_path.with_suffix("." + kwargs["format"])
# Convert figure number to Figure.
fig = plt.figure(fig_num)
# Deal with animations
if anim := anims.get(fig):
image_rsts.append(_anim_rst(anim, image_path, gallery_conf))
continue
# get fig titles
fig_titles = _matplotlib_fig_titles(fig)
to_rgba = matplotlib.colors.colorConverter.to_rgba
# shallow copy should be fine here, just want to avoid changing
# "kwargs" for subsequent figures processed by the loop
these_kwargs = kwargs.copy()
for attr in ["facecolor", "edgecolor"]:
fig_attr = getattr(fig, "get_" + attr)()
default_attr = matplotlib.rcParams["figure." + attr]
if to_rgba(fig_attr) != to_rgba(default_attr) and attr not in kwargs:
these_kwargs[attr] = fig_attr
# save the figures, and populate the srcsetpaths
try:
fig.savefig(image_path, **these_kwargs)
dpi0 = matplotlib.rcParams["savefig.dpi"]
if dpi0 == "figure":
dpi0 = fig.dpi
dpi0 = these_kwargs.get("dpi", dpi0)
srcsetpaths = {0: image_path}
# save other srcset paths, keyed by multiplication factor:
for mult in srcset:
multst = f"{mult:.2f}".replace(".", "_")
name = f"{image_path.stem}_{multst}x{image_path.suffix}"
hipath = image_path.parent / PurePosixPath(name)
hikwargs = {**these_kwargs, "dpi": mult * dpi0}
fig.savefig(hipath, **hikwargs)
srcsetpaths[mult] = hipath
srcsetpaths = [srcsetpaths]
except Exception:
plt.close("all")
raise
if "images" in gallery_conf["compress_images"]:
optipng(str(image_path), gallery_conf["compress_images_args"])
for hipath in srcsetpaths[0].items():
optipng(str(hipath), gallery_conf["compress_images_args"])
image_rsts.append(
figure_rst(
[image_path],
gallery_conf["src_dir"],
fig_titles,
srcsetpaths=srcsetpaths,
)
)
# Determine whether single-img should be converted to multi-img
convert_to_multi_image = True # default is to convert
if block_vars.get("multi_image") is not None: # block setting takes precedence
convert_to_multi_image = block_vars["multi_image"] != "single"
elif block_vars.get("file_conf") is not None: # then file setting
convert_to_multi_image = block_vars["file_conf"].get("multi_image") != "single"
plt.close("all")
rst = ""
if len(image_rsts) == 1:
rst = image_rsts[0]
elif len(image_rsts) > 1:
if convert_to_multi_image:
image_rsts = [
re.sub(
r":class: sphx-glr-single-img", ":class: sphx-glr-multi-img", image
)
for image in image_rsts
]
image_rsts = [
HLIST_IMAGE_MATPLOTLIB + indent(image, " " * 6) for image in image_rsts
]
rst = HLIST_HEADER + "".join(image_rsts)
return rst
def _anim_rst(anim, image_path, gallery_conf):
from matplotlib import rcParams
from matplotlib.animation import FFMpegWriter, ImageMagickWriter
# output the thumbnail as the image, as it will just be copied
# if it's the file thumbnail
fig = anim._fig
image_path = image_path.with_suffix(".gif")
fig_size = fig.get_size_inches()
thumb_size = gallery_conf["thumbnail_size"]
use_dpi = round(min(t_s / f_s for t_s, f_s in zip(thumb_size, fig_size)))
if FFMpegWriter.isAvailable():
writer = "ffmpeg"
elif ImageMagickWriter.isAvailable():
writer = "imagemagick"
else:
writer = None
anim.save(str(image_path), writer=writer, dpi=use_dpi)
_, fmt = gallery_conf["matplotlib_animations"]
# Formats that are embedded in rst
html = None
if fmt is None:
html = anim._repr_html_()
if html is None: # plt.rcParams['animation.html'] == 'none'
html = anim.to_jshtml()
elif fmt == "html5":
html = anim.to_html5_video()
elif fmt == "jshtml":
html = anim.to_jshtml()
if html is not None:
html = indent(html, " ")
return _ANIMATION_RST.format(html)
# Formats that are saved and use `video` directive
video = image_path.with_suffix(f".{fmt}")
anim.save(video)
options = ["autoplay"]
if getattr(anim, "_repeat", False):
options.append("loop")
dpi = rcParams["savefig.dpi"]
if dpi == "figure":
dpi = fig.dpi
video_uri = video.relative_to(gallery_conf["src_dir"]).as_posix()
html = _ANIMATION_VIDEO_RST.format(
video=f"/{video_uri}",
width=int(fig_size[0] * dpi),
height=int(fig_size[1] * dpi),
options="".join(f" :{opt}:\n" for opt in options),
)
return html
_scraper_dict = dict(
matplotlib=matplotlib_scraper,
)
[docs]
class ImagePathIterator:
"""Iterate over image paths for a given example.
Parameters
----------
image_path : str
The template image path.
"""
def __init__(self, image_path):
self.image_path = image_path
self.paths = list()
self._stop = 1000000
def __len__(self):
"""Return the number of image paths used.
Returns
-------
n_paths : int
The number of paths.
"""
return len(self.paths)
def __iter__(self):
"""Iterate over paths.
Returns
-------
paths : iterable of str
This enables the use of this Python pattern::
>>> for epoch in epochs: # doctest: +SKIP
>>> print(epoch) # doctest: +SKIP
Where ``epoch`` is given by successive outputs of
:func:`mne.Epochs.next`.
"""
# we should really never have 1e6, let's prevent some user pain
for ii in range(self._stop):
yield self.next()
else:
raise ExtensionError(f"Generated over {self._stop} images")
[docs]
def next(self):
"""Return the next image path, with numbering starting at 1."""
return self.__next__()
def __next__(self):
# The +1 here is because we start image numbering at 1 in filenames
path = self.image_path.format(len(self) + 1)
self.paths.append(path)
return path
# For now, these are what we support
# Update advanced.rst if this list is changed
_KNOWN_IMG_EXTS = ("png", "svg", "jpg", "gif", "webp")
def _find_image_ext(path):
"""Find an image, tolerant of different file extensions."""
path = os.path.splitext(path)[0]
for ext in _KNOWN_IMG_EXTS:
this_path = f"{path}.{ext}"
if os.path.isfile(this_path):
break
else:
ext = "png"
return (f"{path}.{ext}", ext)
def _get_srcset_st(sources_dir, hinames):
"""Create the srcset string for including on the rst line.
For example; `sources_dir` might be `/home/sample-proj/source`,
hinames posix paths:
0: /home/sample-proj/source/plot_types/images/img1.png,
2.0: /home/sample-proj/source/plot_types/images/img1_2_00x.png,
The result would be:
'/plot_types/basic/images/sphx_glr_pie_001.png,
/plot_types/basic/images/sphx_glr_pie_001_2_00x.png 2.00x'
"""
srcst = ""
for k in hinames.keys():
path = os.path.relpath(hinames[k], sources_dir).replace(os.sep, "/").lstrip("/")
srcst += "/" + path
if k == 0:
srcst += ", "
else:
srcst += f" {k:1.2f}x, "
if srcst[-2:] == ", ":
srcst = srcst[:-2]
srcst += ""
return srcst
def _single_line_sanitize(s):
"""Remove problematic newlines."""
# For example, when setting a :alt: for an image, it shouldn't have \n
# This is a function in case we end up finding other things to replace
return s.replace("\n", " ")
# The following strings are used when we have several pictures: we use
# an html div tag that our CSS uses to turn the lists into horizontal
# lists.
HLIST_HEADER = """
.. rst-class:: sphx-glr-horizontal
"""
HLIST_IMAGE_MATPLOTLIB = """
*
"""
HLIST_SG_TEMPLATE = """
*
.. image-sg:: /%s
:alt: %s
:srcset: %s
:class: sphx-glr-multi-img
"""
SG_IMAGE = """
.. image-sg:: /%s
:alt: %s
:srcset: %s
:class: sphx-glr-single-img
"""
# keep around for back-compat:
SINGLE_IMAGE = """
.. image:: /%s
:alt: %s
:class: sphx-glr-single-img
"""
###############################################################################
# Module resetting
def _reset_matplotlib(gallery_conf, fname):
"""Reset matplotlib."""
mpl, plt = _import_matplotlib()
plt.rcdefaults()
importlib.reload(mpl.units)
importlib.reload(mpl.dates)
importlib.reload(mpl.category)
def _reset_seaborn(gallery_conf, fname):
"""Reset seaborn."""
seaborn_module = sys.modules.get("seaborn")
if seaborn_module is not None:
seaborn_module.reset_defaults()
_reset_dict = {
"matplotlib": _reset_matplotlib,
"seaborn": _reset_seaborn,
}
[docs]
def clean_modules(gallery_conf, fname, when):
"""Remove, unload, or reset modules.
After a script is executed it can load a variety of settings that one
does not want to influence in other examples in the gallery.
Parameters
----------
gallery_conf : dict
The gallery configuration.
fname : str or None
The example being run. Will be None when this is called entering
a directory of examples to be built.
when : str
Whether this module is run before or after examples.
This parameter is only forwarded when the callables accept 3
parameters.
"""
from .gen_rst import _get_callables
for reset_module in _get_callables(gallery_conf, "reset_modules"):
sig = inspect.signature(reset_module)
if len(sig.parameters) == 3:
third_param = list(sig.parameters.keys())[2]
if third_param != "when":
raise ValueError(
f"3rd parameter in {reset_module.__name__} "
"function signature must be 'when', "
f"got {third_param}"
)
reset_module(gallery_conf, fname, when=when)
else:
reset_module(gallery_conf, fname)