== None to is None

IPython/core/tests/test_formatters.py

@@ -1,542 +1,542 b''
 """Tests for the Formatters."""
 
 import warnings
 from math import pi
 
 try:
     import numpy
 except:
     numpy = None
 import nose.tools as nt
 
 from IPython import get_ipython
 from traitlets.config import Config
 from IPython.core.formatters import (
     PlainTextFormatter, HTMLFormatter, PDFFormatter, _mod_name_key,
     DisplayFormatter, JSONFormatter,
 )
 from IPython.utils.io import capture_output
 
 class A(object):
     def __repr__(self):
         return 'A()'
 
 class B(A):
     def __repr__(self):
         return 'B()'
 
 class C:
     pass
 
 class BadRepr(object):
     def __repr__(self):
         raise ValueError("bad repr")
 
 class BadPretty(object):
     _repr_pretty_ = None
 
 class GoodPretty(object):
     def _repr_pretty_(self, pp, cycle):
         pp.text('foo')
 
     def __repr__(self):
         return 'GoodPretty()'
 
 def foo_printer(obj, pp, cycle):
     pp.text('foo')
 
 def test_pretty():
     f = PlainTextFormatter()
     f.for_type(A, foo_printer)
     assert f(A()) == "foo"
     assert f(B()) == "B()"
     assert f(GoodPretty()) == "foo"
     # Just don't raise an exception for the following:
     f(BadPretty())
 
     f.pprint = False
     assert f(A()) == "A()"
     assert f(B()) == "B()"
     assert f(GoodPretty()) == "GoodPretty()"
 
 
 def test_deferred():
     f = PlainTextFormatter()
 
 def test_precision():
     """test various values for float_precision."""
     f = PlainTextFormatter()
     assert f(pi) == repr(pi)
     f.float_precision = 0
     if numpy:
         po = numpy.get_printoptions()
         assert po["precision"] == 0
     assert f(pi) == "3"
     f.float_precision = 2
     if numpy:
         po = numpy.get_printoptions()
         assert po["precision"] == 2
     assert f(pi) == "3.14"
     f.float_precision = "%g"
     if numpy:
         po = numpy.get_printoptions()
         assert po["precision"] == 2
     assert f(pi) == "3.14159"
     f.float_precision = "%e"
     assert f(pi) == "3.141593e+00"
     f.float_precision = ""
     if numpy:
         po = numpy.get_printoptions()
         assert po["precision"] == 8
     assert f(pi) == repr(pi)
 
 
 def test_bad_precision():
     """test various invalid values for float_precision."""
     f = PlainTextFormatter()
     def set_fp(p):
         f.float_precision=p
     nt.assert_raises(ValueError, set_fp, '%')
     nt.assert_raises(ValueError, set_fp, '%.3f%i')
     nt.assert_raises(ValueError, set_fp, 'foo')
     nt.assert_raises(ValueError, set_fp, -1)
 
 def test_for_type():
     f = PlainTextFormatter()
     
     # initial return, None
     nt.assert_is(f.for_type(C, foo_printer), None)
     # no func queries
     nt.assert_is(f.for_type(C), foo_printer)
     # shouldn't change anything
     nt.assert_is(f.for_type(C), foo_printer)
     # None should do the same
     nt.assert_is(f.for_type(C, None), foo_printer)
     nt.assert_is(f.for_type(C, None), foo_printer)
 
 def test_for_type_string():
     f = PlainTextFormatter()
     
     type_str = '%s.%s' % (C.__module__, 'C')
     
     # initial return, None
     nt.assert_is(f.for_type(type_str, foo_printer), None)
     # no func queries
     nt.assert_is(f.for_type(type_str), foo_printer)
     nt.assert_in(_mod_name_key(C), f.deferred_printers)
     nt.assert_is(f.for_type(C), foo_printer)
     nt.assert_not_in(_mod_name_key(C), f.deferred_printers)
     nt.assert_in(C, f.type_printers)
 
 def test_for_type_by_name():
     f = PlainTextFormatter()
     
     mod = C.__module__
     
     # initial return, None
     nt.assert_is(f.for_type_by_name(mod, 'C', foo_printer), None)
     # no func queries
     nt.assert_is(f.for_type_by_name(mod, 'C'), foo_printer)
     # shouldn't change anything
     nt.assert_is(f.for_type_by_name(mod, 'C'), foo_printer)
     # None should do the same
     nt.assert_is(f.for_type_by_name(mod, 'C', None), foo_printer)
     nt.assert_is(f.for_type_by_name(mod, 'C', None), foo_printer)
 
 def test_lookup():
     f = PlainTextFormatter()
     
     f.for_type(C, foo_printer)
     nt.assert_is(f.lookup(C()), foo_printer)
     with nt.assert_raises(KeyError):
         f.lookup(A())
 
 def test_lookup_string():
     f = PlainTextFormatter()
     type_str = '%s.%s' % (C.__module__, 'C')
     
     f.for_type(type_str, foo_printer)
     nt.assert_is(f.lookup(C()), foo_printer)
     # should move from deferred to imported dict
     nt.assert_not_in(_mod_name_key(C), f.deferred_printers)
     nt.assert_in(C, f.type_printers)
 
 def test_lookup_by_type():
     f = PlainTextFormatter()
     f.for_type(C, foo_printer)
     nt.assert_is(f.lookup_by_type(C), foo_printer)
     with nt.assert_raises(KeyError):
         f.lookup_by_type(A)
 
 def test_lookup_by_type_string():
     f = PlainTextFormatter()
     type_str = '%s.%s' % (C.__module__, 'C')
     f.for_type(type_str, foo_printer)
     
     # verify insertion
     nt.assert_in(_mod_name_key(C), f.deferred_printers)
     nt.assert_not_in(C, f.type_printers)
     
     nt.assert_is(f.lookup_by_type(type_str), foo_printer)
     # lookup by string doesn't cause import
     nt.assert_in(_mod_name_key(C), f.deferred_printers)
     nt.assert_not_in(C, f.type_printers)
     
     nt.assert_is(f.lookup_by_type(C), foo_printer)
     # should move from deferred to imported dict
     nt.assert_not_in(_mod_name_key(C), f.deferred_printers)
     nt.assert_in(C, f.type_printers)
 
 def test_in_formatter():
     f = PlainTextFormatter()
     f.for_type(C, foo_printer)
     type_str = '%s.%s' % (C.__module__, 'C')
     nt.assert_in(C, f)
     nt.assert_in(type_str, f)
 
 def test_string_in_formatter():
     f = PlainTextFormatter()
     type_str = '%s.%s' % (C.__module__, 'C')
     f.for_type(type_str, foo_printer)
     nt.assert_in(type_str, f)
     nt.assert_in(C, f)
 
 def test_pop():
     f = PlainTextFormatter()
     f.for_type(C, foo_printer)
     nt.assert_is(f.lookup_by_type(C), foo_printer)
     nt.assert_is(f.pop(C, None), foo_printer)
     f.for_type(C, foo_printer)
     nt.assert_is(f.pop(C), foo_printer)
     with nt.assert_raises(KeyError):
         f.lookup_by_type(C)
     with nt.assert_raises(KeyError):
         f.pop(C)
     with nt.assert_raises(KeyError):
         f.pop(A)
     nt.assert_is(f.pop(A, None), None)
 
 def test_pop_string():
     f = PlainTextFormatter()
     type_str = '%s.%s' % (C.__module__, 'C')
     
     with nt.assert_raises(KeyError):
         f.pop(type_str)
     
     f.for_type(type_str, foo_printer)
     f.pop(type_str)
     with nt.assert_raises(KeyError):
         f.lookup_by_type(C)
     with nt.assert_raises(KeyError):
         f.pop(type_str)
 
     f.for_type(C, foo_printer)
     nt.assert_is(f.pop(type_str, None), foo_printer)
     with nt.assert_raises(KeyError):
         f.lookup_by_type(C)
     with nt.assert_raises(KeyError):
         f.pop(type_str)
     nt.assert_is(f.pop(type_str, None), None)
     
 
 def test_error_method():
     f = HTMLFormatter()
     class BadHTML(object):
         def _repr_html_(self):
             raise ValueError("Bad HTML")
     bad = BadHTML()
     with capture_output() as captured:
         result = f(bad)
     nt.assert_is(result, None)
     nt.assert_in("Traceback", captured.stdout)
     nt.assert_in("Bad HTML", captured.stdout)
     nt.assert_in("_repr_html_", captured.stdout)
 
 def test_nowarn_notimplemented():
     f = HTMLFormatter()
     class HTMLNotImplemented(object):
         def _repr_html_(self):
             raise NotImplementedError
     h = HTMLNotImplemented()
     with capture_output() as captured:
         result = f(h)
     nt.assert_is(result, None)
     assert "" == captured.stderr
     assert "" == captured.stdout
 
 
 def test_warn_error_for_type():
     f = HTMLFormatter()
     f.for_type(int, lambda i: name_error)
     with capture_output() as captured:
         result = f(5)
     nt.assert_is(result, None)
     nt.assert_in("Traceback", captured.stdout)
     nt.assert_in("NameError", captured.stdout)
     nt.assert_in("name_error", captured.stdout)
 
 def test_error_pretty_method():
     f = PlainTextFormatter()
     class BadPretty(object):
         def _repr_pretty_(self):
             return "hello"
     bad = BadPretty()
     with capture_output() as captured:
         result = f(bad)
     nt.assert_is(result, None)
     nt.assert_in("Traceback", captured.stdout)
     nt.assert_in("_repr_pretty_", captured.stdout)
     nt.assert_in("given", captured.stdout)
     nt.assert_in("argument", captured.stdout)
 
 
 def test_bad_repr_traceback():
     f = PlainTextFormatter()
     bad = BadRepr()
     with capture_output() as captured:
         result = f(bad)
     # catches error, returns None
     nt.assert_is(result, None)
     nt.assert_in("Traceback", captured.stdout)
     nt.assert_in("__repr__", captured.stdout)
     nt.assert_in("ValueError", captured.stdout)
 
 
 class MakePDF(object):
     def _repr_pdf_(self):
         return 'PDF'
 
 def test_pdf_formatter():
     pdf = MakePDF()
     f = PDFFormatter()
     assert f(pdf) == "PDF"
 
 
 def test_print_method_bound():
     f = HTMLFormatter()
     class MyHTML(object):
         def _repr_html_(self):
             return "hello"
     with capture_output() as captured:
         result = f(MyHTML)
     nt.assert_is(result, None)
     nt.assert_not_in("FormatterWarning", captured.stderr)
 
     with capture_output() as captured:
         result = f(MyHTML())
     assert result == "hello"
     assert captured.stderr == ""
 
 
 def test_print_method_weird():
 
     class TextMagicHat(object):
         def __getattr__(self, key):
             return key
 
     f = HTMLFormatter()
 
     text_hat = TextMagicHat()
     assert text_hat._repr_html_ == "_repr_html_"
     with capture_output() as captured:
         result = f(text_hat)
     
     nt.assert_is(result, None)
     nt.assert_not_in("FormatterWarning", captured.stderr)
 
     class CallableMagicHat(object):
         def __getattr__(self, key):
             return lambda : key
     
     call_hat = CallableMagicHat()
     with capture_output() as captured:
         result = f(call_hat)
 
-    assert result == None
+    assert result is None
 
     class BadReprArgs(object):
         def _repr_html_(self, extra, args):
             return "html"
     
     bad = BadReprArgs()
     with capture_output() as captured:
         result = f(bad)
     
     nt.assert_is(result, None)
     nt.assert_not_in("FormatterWarning", captured.stderr)
 
 
 def test_format_config():
     """config objects don't pretend to support fancy reprs with lazy attrs"""
     f = HTMLFormatter()
     cfg = Config()
     with capture_output() as captured:
         result = f(cfg)
     nt.assert_is(result, None)
     assert captured.stderr == ""
 
     with capture_output() as captured:
         result = f(Config)
     nt.assert_is(result, None)
     assert captured.stderr == ""
 
 
 def test_pretty_max_seq_length():
     f = PlainTextFormatter(max_seq_length=1)
     lis = list(range(3))
     text = f(lis)
     assert text == "[0, ...]"
     f.max_seq_length = 0
     text = f(lis)
     assert text == "[0, 1, 2]"
     text = f(list(range(1024)))
     lines = text.splitlines()
     assert len(lines) == 1024
 
 
 def test_ipython_display_formatter():
     """Objects with _ipython_display_ defined bypass other formatters"""
     f = get_ipython().display_formatter
     catcher = []
     class SelfDisplaying(object):
         def _ipython_display_(self):
             catcher.append(self)
 
     class NotSelfDisplaying(object):
         def __repr__(self):
             return "NotSelfDisplaying"
         
         def _ipython_display_(self):
             raise NotImplementedError
     
     save_enabled = f.ipython_display_formatter.enabled
     f.ipython_display_formatter.enabled = True
     
     yes = SelfDisplaying()
     no = NotSelfDisplaying()
 
     d, md = f.format(no)
     assert d == {"text/plain": repr(no)}
     assert md == {}
     assert catcher == []
 
     d, md = f.format(yes)
     assert d == {}
     assert md == {}
     assert catcher == [yes]
 
     f.ipython_display_formatter.enabled = save_enabled
 
 
 def test_json_as_string_deprecated():
     class JSONString(object):
         def _repr_json_(self):
             return '{}'
     
     f = JSONFormatter()
     with warnings.catch_warnings(record=True) as w:
         d = f(JSONString())
     assert d == {}
     assert len(w) == 1
 
 
 def test_repr_mime():
     class HasReprMime(object):
         def _repr_mimebundle_(self, include=None, exclude=None):
             return {
                 'application/json+test.v2': {
                     'x': 'y'
                 },
                 'plain/text' : '<HasReprMime>',
                 'image/png' : 'i-overwrite'
             }
 
         def _repr_png_(self):
             return 'should-be-overwritten'
         def _repr_html_(self):
             return '<b>hi!</b>'
     
     f = get_ipython().display_formatter
     html_f = f.formatters['text/html']
     save_enabled = html_f.enabled
     html_f.enabled = True
     obj = HasReprMime()
     d, md = f.format(obj)
     html_f.enabled = save_enabled
 
     assert sorted(d) == [
         "application/json+test.v2",
         "image/png",
         "plain/text",
         "text/html",
         "text/plain",
     ]
     assert md == {}
 
     d, md = f.format(obj, include={"image/png"})
     assert list(d.keys()) == [
         "image/png"
     ], "Include should filter out even things from repr_mimebundle"
 
     assert d["image/png"] == "i-overwrite", "_repr_mimebundle_ take precedence"
 
 
 def test_pass_correct_include_exclude():
     class Tester(object):
 
         def __init__(self, include=None, exclude=None):
             self.include = include
             self.exclude = exclude
 
         def _repr_mimebundle_(self, include, exclude, **kwargs):
             if include and (include != self.include):
                 raise ValueError('include got modified: display() may be broken.')
             if exclude and (exclude != self.exclude):
                 raise ValueError('exclude got modified: display() may be broken.')
 
             return None
 
     include = {'a', 'b', 'c'}
     exclude = {'c', 'e' , 'f'}
 
     f = get_ipython().display_formatter
     f.format(Tester(include=include, exclude=exclude), include=include, exclude=exclude)
     f.format(Tester(exclude=exclude), exclude=exclude)
     f.format(Tester(include=include), include=include)
 
 
 def test_repr_mime_meta():
     class HasReprMimeMeta(object):
         def _repr_mimebundle_(self, include=None, exclude=None):
             data = {
                 'image/png': 'base64-image-data',
             }
             metadata = {
                 'image/png': {
                     'width': 5,
                     'height': 10,
                 }
             }
             return (data, metadata)
     
     f = get_ipython().display_formatter
     obj = HasReprMimeMeta()
     d, md = f.format(obj)
     assert sorted(d) == ["image/png", "text/plain"]
     assert md == {
         "image/png": {
             "width": 5,
             "height": 10,
         }
     }
 
 
 def test_repr_mime_failure():
     class BadReprMime(object):
         def _repr_mimebundle_(self, include=None, exclude=None):
             raise RuntimeError
 
     f = get_ipython().display_formatter
     obj = BadReprMime()
     d, md = f.format(obj)
     assert "text/plain" in d

IPython/lib/tests/test_latextools.py

@@ -1,191 +1,191 b''
 """Tests for IPython.utils.path.py"""
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from contextlib import contextmanager
 from unittest.mock import patch
 
 import nose.tools as nt
 import pytest
 
 from IPython.lib import latextools
 from IPython.testing.decorators import (
     onlyif_cmds_exist,
     skipif_not_matplotlib,
     skip_iptest_but_not_pytest,
 )
 from IPython.utils.process import FindCmdError
 
 
 @pytest.mark.parametrize('command', ['latex', 'dvipng'])
 @skip_iptest_but_not_pytest
 def test_check_latex_to_png_dvipng_fails_when_no_cmd(command):
     def mock_find_cmd(arg):
         if arg == command:
             raise FindCmdError
 
     with patch.object(latextools, "find_cmd", mock_find_cmd):
-        assert latextools.latex_to_png_dvipng("whatever", True) == None
+        assert latextools.latex_to_png_dvipng("whatever", True) is None
 
 
 @contextmanager
 def no_op(*args, **kwargs):
     yield
 
 
 @skip_iptest_but_not_pytest
 @onlyif_cmds_exist("latex", "dvipng")
 @pytest.mark.parametrize("s, wrap", [(u"$$x^2$$", False), (u"x^2", True)])
 def test_latex_to_png_dvipng_runs(s, wrap):
     """
     Test that latex_to_png_dvipng just runs without error.
     """
     def mock_kpsewhich(filename):
         assert filename == "breqn.sty"
         return None
 
     latextools.latex_to_png_dvipng(s, wrap)
 
     with patch_latextool(mock_kpsewhich):
         latextools.latex_to_png_dvipng(s, wrap)
 
 
 def mock_kpsewhich(filename):
     assert filename == "breqn.sty"
     return None
 
 @contextmanager
 def patch_latextool(mock=mock_kpsewhich):
     with patch.object(latextools, "kpsewhich", mock):
         yield
 
 @pytest.mark.parametrize('context', [no_op, patch_latextool])
 @pytest.mark.parametrize('s_wrap', [("$x^2$", False), ("x^2", True)])
 @skip_iptest_but_not_pytest
 def test_latex_to_png_mpl_runs(s_wrap, context):
     """
     Test that latex_to_png_mpl just runs without error.
     """
     try:
         import matplotlib
     except ImportError:
         pytest.skip("This needs matplotlib to be available")
         return
     s, wrap = s_wrap
     with context():
         latextools.latex_to_png_mpl(s, wrap)
 
 @skipif_not_matplotlib
 def test_latex_to_html():
     img = latextools.latex_to_html("$x^2$")
     assert "data:image/png;base64,iVBOR" in img
 
 
 def test_genelatex_no_wrap():
     """
     Test genelatex with wrap=False.
     """
     def mock_kpsewhich(filename):
         assert False, ("kpsewhich should not be called "
                        "(called with {0})".format(filename))
 
     with patch_latextool(mock_kpsewhich):
         assert '\n'.join(latextools.genelatex("body text", False)) == r'''\documentclass{article}
 \usepackage{amsmath}
 \usepackage{amsthm}
 \usepackage{amssymb}
 \usepackage{bm}
 \pagestyle{empty}
 \begin{document}
 body text
 \end{document}'''
 
 
 def test_genelatex_wrap_with_breqn():
     """
     Test genelatex with wrap=True for the case breqn.sty is installed.
     """
     def mock_kpsewhich(filename):
         assert filename == "breqn.sty"
         return "path/to/breqn.sty"
 
     with patch_latextool(mock_kpsewhich):
         assert '\n'.join(latextools.genelatex("x^2", True)) == r'''\documentclass{article}
 \usepackage{amsmath}
 \usepackage{amsthm}
 \usepackage{amssymb}
 \usepackage{bm}
 \usepackage{breqn}
 \pagestyle{empty}
 \begin{document}
 \begin{dmath*}
 x^2
 \end{dmath*}
 \end{document}'''
 
 
 def test_genelatex_wrap_without_breqn():
     """
     Test genelatex with wrap=True for the case breqn.sty is not installed.
     """
     def mock_kpsewhich(filename):
         assert filename == "breqn.sty"
         return None
 
     with patch_latextool(mock_kpsewhich):
         assert '\n'.join(latextools.genelatex("x^2", True)) == r'''\documentclass{article}
 \usepackage{amsmath}
 \usepackage{amsthm}
 \usepackage{amssymb}
 \usepackage{bm}
 \pagestyle{empty}
 \begin{document}
 $$x^2$$
 \end{document}'''
 
 
 @skipif_not_matplotlib
 @onlyif_cmds_exist('latex', 'dvipng')
 def test_latex_to_png_color():
     """
     Test color settings for latex_to_png.
     """
     latex_string = "$x^2$"
     default_value = latextools.latex_to_png(latex_string, wrap=False)
     default_hexblack = latextools.latex_to_png(latex_string, wrap=False,
                                                color='#000000')
     dvipng_default = latextools.latex_to_png_dvipng(latex_string, False)
     dvipng_black = latextools.latex_to_png_dvipng(latex_string, False, 'Black')
     assert dvipng_default == dvipng_black
     mpl_default = latextools.latex_to_png_mpl(latex_string, False)
     mpl_black = latextools.latex_to_png_mpl(latex_string, False, 'Black')
     assert mpl_default == mpl_black
     assert default_value in [dvipng_black, mpl_black]
     assert default_hexblack in [dvipng_black, mpl_black]
 
     # Test that dvips name colors can be used without error
     dvipng_maroon = latextools.latex_to_png_dvipng(latex_string, False,
                                                    'Maroon')
     # And that it doesn't return the black one
     assert dvipng_black != dvipng_maroon
 
     mpl_maroon = latextools.latex_to_png_mpl(latex_string, False, 'Maroon')
     assert mpl_black != mpl_maroon
     mpl_white = latextools.latex_to_png_mpl(latex_string, False, 'White')
     mpl_hexwhite = latextools.latex_to_png_mpl(latex_string, False, '#FFFFFF')
     assert mpl_white == mpl_hexwhite
 
     mpl_white_scale = latextools.latex_to_png_mpl(latex_string, False,
                                                   'White', 1.2)
     assert mpl_white != mpl_white_scale
 
 
 def test_latex_to_png_invalid_hex_colors():
     """
     Test that invalid hex colors provided to dvipng gives an exception.
     """
     latex_string = "$x^2$"
     nt.assert_raises(ValueError, lambda: latextools.latex_to_png(latex_string,
                                         backend='dvipng', color="#f00bar"))
     nt.assert_raises(ValueError, lambda: latextools.latex_to_png(latex_string,
                                         backend='dvipng', color="#f00"))