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Reset the interactive namespace __warningregistry__ before executing code...
Reset the interactive namespace __warningregistry__ before executing code Fixes #6611. Idea: Right now, people often don't see important warnings when running code in IPython, because (to a first approximation) any given warning will only issue once per session. Blink and you'll miss it! This is a very common contributor to confused emails to numpy-discussion. E.g.: In [5]: 1 / my_array_with_random_contents /home/njs/.user-python2.7-64bit-3/bin/ipython:1: RuntimeWarning: divide by zero encountered in divide #!/home/njs/.user-python2.7-64bit-3/bin/python Out[5]: array([ 1.77073316, -2.29765021, -2.01800811, ..., 1.13871243, -1.08302964, -8.6185091 ]) Oo, right, guess I gotta be careful of those zeros -- thanks, numpy, for giving me that warning! A few days later: In [592]: 1 / some_other_array Out[592]: array([ 3.07735763, 0.50769289, 0.83984078, ..., -0.67563917, -0.85736257, -1.36511271]) Oops, it turns out that this array had a zero in it too, and that's going to bite me later. But no warning this time! The effect of this commit is to make it so that warnings triggered by the code in cell 5 do *not* suppress warnings triggered by the code in cell 592. Note that this only applies to warnings triggered *directly* by code entered interactively -- if somepkg.foo() calls anotherpkg.bad_func() which issues a warning, then this warning will still only be displayed once, even if multiple cells call somepkg.foo(). But if cell 5 and cell 592 both call anotherpkg.bad_func() directly, then both will get warnings. (Important exception: if foo() is defined *interactively*, and calls anotherpkg.bad_func(), then every cell that calls foo() will display the warning again. This is unavoidable without fixes to CPython upstream.) Explanation: Python's warning system has some weird quirks. By default, it tries to suppress duplicate warnings, where "duplicate" means the same warning message triggered twice by the same line of code. This requires determining which line of code is responsible for triggering a warning, and this is controlled by the stacklevel= argument to warnings.warn. Basically, though, the idea is that if foo() calls bar() which calls baz() which calls some_deprecated_api(), then baz() will get counted as being "responsible", and the warning system will make a note that the usage of some_deprecated_api() inside baz() has already been warned about and doesn't need to be warned about again. So far so good. To accomplish this, obviously, there has to be a record of somewhere which line this was. You might think that this would be done by recording the filename:linenumber pair in a dict inside the warnings module, or something like that. You would be wrong. What actually happens is that the warnings module will use stack introspection to reach into baz()'s execution environment, create a global (module-level) variable there named __warningregistry__, and then, inside this dictionary, record just the line number. Basically, it assumes that any given module contains only one line 1, only one line 2, etc., so storing the filename is irrelevant. Obviously for interactive code this is totally wrong -- all cells share the same execution environment and global namespace, and they all contain a new line 1. Currently the warnings module treats these as if they were all the same line. In fact they are not the same line; once we have executed a given chunk of code, we will never see those particular lines again. As soon as a given chunk of code finishes executing, its line number labels become meaningless, and the corresponding warning registry entries become meaningless as well. Therefore, with this patch we delete the __warningregistry__ each time we execute a new block of code.

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test_pylabtools.py
241 lines | 7.6 KiB | text/x-python | PythonLexer
"""Tests for pylab tools module.
"""
#-----------------------------------------------------------------------------
# Copyright (c) 2011, the IPython Development Team.
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the file COPYING.txt, distributed with this software.
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
from __future__ import print_function
from io import UnsupportedOperation, BytesIO
import matplotlib
matplotlib.use('Agg')
from matplotlib.figure import Figure
from nose import SkipTest
import nose.tools as nt
from matplotlib import pyplot as plt
import numpy as np
# Our own imports
from IPython.core.getipython import get_ipython
from IPython.core.interactiveshell import InteractiveShell
from IPython.core.display import _PNG, _JPEG
from .. import pylabtools as pt
from IPython.testing import decorators as dec
#-----------------------------------------------------------------------------
# Globals and constants
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Local utilities
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Classes and functions
#-----------------------------------------------------------------------------
def test_figure_to_svg():
# simple empty-figure test
fig = plt.figure()
nt.assert_equal(pt.print_figure(fig, 'svg'), None)
plt.close('all')
# simple check for at least svg-looking output
fig = plt.figure()
ax = fig.add_subplot(1,1,1)
ax.plot([1,2,3])
plt.draw()
svg = pt.print_figure(fig, 'svg')[:100].lower()
nt.assert_in(u'doctype svg', svg)
def _check_pil_jpeg_bytes():
"""Skip if PIL can't write JPEGs to BytesIO objects"""
# PIL's JPEG plugin can't write to BytesIO objects
# Pillow fixes this
from PIL import Image
buf = BytesIO()
img = Image.new("RGB", (4,4))
try:
img.save(buf, 'jpeg')
except Exception as e:
ename = e.__class__.__name__
raise SkipTest("PIL can't write JPEG to BytesIO: %s: %s" % (ename, e))
@dec.skip_without("PIL.Image")
def test_figure_to_jpeg():
_check_pil_jpeg_bytes()
# simple check for at least jpeg-looking output
fig = plt.figure()
ax = fig.add_subplot(1,1,1)
ax.plot([1,2,3])
plt.draw()
jpeg = pt.print_figure(fig, 'jpeg', quality=50)[:100].lower()
assert jpeg.startswith(_JPEG)
def test_retina_figure():
fig = plt.figure()
ax = fig.add_subplot(1,1,1)
ax.plot([1,2,3])
plt.draw()
png, md = pt.retina_figure(fig)
assert png.startswith(_PNG)
nt.assert_in('width', md)
nt.assert_in('height', md)
_fmt_mime_map = {
'png': 'image/png',
'jpeg': 'image/jpeg',
'pdf': 'application/pdf',
'retina': 'image/png',
'svg': 'image/svg+xml',
}
def test_select_figure_formats_str():
ip = get_ipython()
for fmt, active_mime in _fmt_mime_map.items():
pt.select_figure_formats(ip, fmt)
for mime, f in ip.display_formatter.formatters.items():
if mime == active_mime:
nt.assert_in(Figure, f)
else:
nt.assert_not_in(Figure, f)
def test_select_figure_formats_kwargs():
ip = get_ipython()
kwargs = dict(quality=10, bbox_inches='tight')
pt.select_figure_formats(ip, 'png', **kwargs)
formatter = ip.display_formatter.formatters['image/png']
f = formatter.lookup_by_type(Figure)
cell = f.__closure__[0].cell_contents
nt.assert_equal(cell, kwargs)
# check that the formatter doesn't raise
fig = plt.figure()
ax = fig.add_subplot(1,1,1)
ax.plot([1,2,3])
plt.draw()
formatter.enabled = True
png = formatter(fig)
assert png.startswith(_PNG)
def test_select_figure_formats_set():
ip = get_ipython()
for fmts in [
{'png', 'svg'},
['png'],
('jpeg', 'pdf', 'retina'),
{'svg'},
]:
active_mimes = {_fmt_mime_map[fmt] for fmt in fmts}
pt.select_figure_formats(ip, fmts)
for mime, f in ip.display_formatter.formatters.items():
if mime in active_mimes:
nt.assert_in(Figure, f)
else:
nt.assert_not_in(Figure, f)
def test_select_figure_formats_bad():
ip = get_ipython()
with nt.assert_raises(ValueError):
pt.select_figure_formats(ip, 'foo')
with nt.assert_raises(ValueError):
pt.select_figure_formats(ip, {'png', 'foo'})
with nt.assert_raises(ValueError):
pt.select_figure_formats(ip, ['retina', 'pdf', 'bar', 'bad'])
def test_import_pylab():
ns = {}
pt.import_pylab(ns, import_all=False)
nt.assert_true('plt' in ns)
nt.assert_equal(ns['np'], np)
class TestPylabSwitch(object):
class Shell(InteractiveShell):
def enable_gui(self, gui):
pass
def setup(self):
import matplotlib
def act_mpl(backend):
matplotlib.rcParams['backend'] = backend
# Save rcParams since they get modified
self._saved_rcParams = matplotlib.rcParams
self._saved_rcParamsOrig = matplotlib.rcParamsOrig
matplotlib.rcParams = dict(backend='Qt4Agg')
matplotlib.rcParamsOrig = dict(backend='Qt4Agg')
# Mock out functions
self._save_am = pt.activate_matplotlib
pt.activate_matplotlib = act_mpl
self._save_ip = pt.import_pylab
pt.import_pylab = lambda *a,**kw:None
self._save_cis = pt.configure_inline_support
pt.configure_inline_support = lambda *a,**kw:None
def teardown(self):
pt.activate_matplotlib = self._save_am
pt.import_pylab = self._save_ip
pt.configure_inline_support = self._save_cis
import matplotlib
matplotlib.rcParams = self._saved_rcParams
matplotlib.rcParamsOrig = self._saved_rcParamsOrig
def test_qt(self):
s = self.Shell()
gui, backend = s.enable_matplotlib(None)
nt.assert_equal(gui, 'qt')
nt.assert_equal(s.pylab_gui_select, 'qt')
gui, backend = s.enable_matplotlib('inline')
nt.assert_equal(gui, 'inline')
nt.assert_equal(s.pylab_gui_select, 'qt')
gui, backend = s.enable_matplotlib('qt')
nt.assert_equal(gui, 'qt')
nt.assert_equal(s.pylab_gui_select, 'qt')
gui, backend = s.enable_matplotlib('inline')
nt.assert_equal(gui, 'inline')
nt.assert_equal(s.pylab_gui_select, 'qt')
gui, backend = s.enable_matplotlib()
nt.assert_equal(gui, 'qt')
nt.assert_equal(s.pylab_gui_select, 'qt')
def test_inline(self):
s = self.Shell()
gui, backend = s.enable_matplotlib('inline')
nt.assert_equal(gui, 'inline')
nt.assert_equal(s.pylab_gui_select, None)
gui, backend = s.enable_matplotlib('inline')
nt.assert_equal(gui, 'inline')
nt.assert_equal(s.pylab_gui_select, None)
gui, backend = s.enable_matplotlib('qt')
nt.assert_equal(gui, 'qt')
nt.assert_equal(s.pylab_gui_select, 'qt')
def test_qt_gtk(self):
s = self.Shell()
gui, backend = s.enable_matplotlib('qt')
nt.assert_equal(gui, 'qt')
nt.assert_equal(s.pylab_gui_select, 'qt')
gui, backend = s.enable_matplotlib('gtk')
nt.assert_equal(gui, 'qt')
nt.assert_equal(s.pylab_gui_select, 'qt')