Skip to content

Improved exception handling on animation failure #12369

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Oct 9, 2018
Merged

Improved exception handling on animation failure #12369

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 7 additions & 0 deletions doc/api/next_api_changes/2018-10-02-AL-animation.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,7 @@
Exception on failing animations changed
```````````````````````````````````````

Previously, subprocess failures in the animation framework would raise either
in a `RuntimeError` or a `ValueError` depending on when the error occurred.
They now raise a `subprocess.CalledProcessError` with attributes set as
documented by the exception class.
56 changes: 21 additions & 35 deletions lib/matplotlib/animation.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -364,22 +364,14 @@ def grab_frame(self, **savefig_kwargs):
command that saves the figure.
'''
_log.debug('MovieWriter.grab_frame: Grabbing frame.')
try:
# re-adjust the figure size in case it has been changed by the
# user. We must ensure that every frame is the same size or
# the movie will not save correctly.
self.fig.set_size_inches(self._w, self._h)
# Tell the figure to save its data to the sink, using the
# frame format and dpi.
self.fig.savefig(self._frame_sink(), format=self.frame_format,
dpi=self.dpi, **savefig_kwargs)
except (RuntimeError, IOError) as e:
out, err = self._proc.communicate()
_log.info('MovieWriter -- Error running proc:\n%s\n%s', out, err)
raise IOError('Error saving animation to file (cause: {0}) '
'Stdout: {1} StdError: {2}. It may help to re-run '
'with logging level set to '
'DEBUG.'.format(e, out, err))
# re-adjust the figure size in case it has been changed by the
# user. We must ensure that every frame is the same size or
# the movie will not save correctly.
self.fig.set_size_inches(self._w, self._h)
# Tell the figure to save its data to the sink, using the
# frame format and dpi.
self.fig.savefig(self._frame_sink(), format=self.frame_format,
dpi=self.dpi, **savefig_kwargs)

def _frame_sink(self):
'''Returns the place to which frames should be written.'''
Expand All @@ -396,15 +388,15 @@ def cleanup(self):
# Use the encoding/errors that universal_newlines would use.
out = TextIOWrapper(BytesIO(out)).read()
err = TextIOWrapper(BytesIO(err)).read()
_log.debug("MovieWriter stdout:\n%s", out)
_log.debug("MovieWriter stderr:\n%s", err)
_log.log(
logging.WARNING if self._proc.returncode else logging.DEBUG,
"MovieWriter stdout:\n%s", out)
_log.log(
logging.WARNING if self._proc.returncode else logging.DEBUG,
"MovieWriter stderr:\n%s", err)
if self._proc.returncode:
raise RuntimeError('Error creating movie, return code {}\n'
'stdout:\n'
'{}\n'
'stderr:\n'
'{}\n'
.format(self._proc.returncode, out, err))
raise subprocess.CalledProcessError(
self._proc.returncode, self._proc.args, out, err)

@classmethod
def bin_path(cls):
Expand Down Expand Up @@ -511,17 +503,11 @@ def grab_frame(self, **savefig_kwargs):
'''
# Overloaded to explicitly close temp file.
_log.debug('MovieWriter.grab_frame: Grabbing frame.')
try:
# Tell the figure to save its data to the sink, using the
# frame format and dpi.
with self._frame_sink() as myframesink:
self.fig.savefig(myframesink, format=self.frame_format,
dpi=self.dpi, **savefig_kwargs)

except RuntimeError:
out, err = self._proc.communicate()
_log.info('MovieWriter -- Error running proc:\n%s\n%s', out, err)
raise
# Tell the figure to save its data to the sink, using the
# frame format and dpi.
with self._frame_sink() as myframesink:
self.fig.savefig(myframesink, format=self.frame_format,
dpi=self.dpi, **savefig_kwargs)

def finish(self):
# Call run here now that all frame grabbing is done. All temp files
Expand Down
10 changes: 4 additions & 6 deletions lib/matplotlib/tests/test_animation.py
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
import os
from pathlib import Path
import subprocess
import sys

import numpy as np
Expand Down Expand Up @@ -237,13 +238,10 @@ def test_cleanup_temporaries(method_name, tmpdir):
assert list(Path(str(tmpdir)).iterdir()) == []


# Currently, this fails with a ValueError after we try to communicate() twice
# with the Popen.
@pytest.mark.xfail
@pytest.mark.skipif(os.name != "posix", reason="requires a POSIX OS")
def test_failing_ffmpeg(tmpdir, monkeypatch):
"""
Test that we correctly raise an OSError when ffmpeg fails.
Test that we correctly raise a CalledProcessError when ffmpeg fails.

To do so, mock ffmpeg using a simple executable shell script that
succeeds when called with no arguments (so that it gets registered by
Expand All @@ -252,12 +250,12 @@ def test_failing_ffmpeg(tmpdir, monkeypatch):
try:
with tmpdir.as_cwd():
monkeypatch.setenv("PATH", ".:" + os.environ["PATH"])
exe_path = Path(tmpdir, "ffmpeg")
exe_path = Path(str(tmpdir), "ffmpeg")
exe_path.write_text("#!/bin/sh\n"
"[[ $@ -eq 0 ]]\n")
os.chmod(str(exe_path), 0o755)
animation.writers.reset_available_writers()
with pytest.raises(OSError):
with pytest.raises(subprocess.CalledProcessError):
make_animation().save("test.mpeg")
finally:
animation.writers.reset_available_writers()