##// END OF EJS Templates
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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basic.tpl
195 lines | 4.6 KiB | application/vnd.groove-tool-template | SmartyLexer
{%- extends 'display_priority.tpl' -%}
{% block codecell %}
<div class="cell border-box-sizing code_cell rendered">
{{ super() }}
</div>
{%- endblock codecell %}
{% block input_group -%}
<div class="input">
{{ super() }}
</div>
{% endblock input_group %}
{% block output_group %}
<div class="output_wrapper">
<div class="output">
{{ super() }}
</div>
</div>
{% endblock output_group %}
{% block in_prompt -%}
<div class="prompt input_prompt">
In&nbsp;[{{ cell.prompt_number }}]:
</div>
{%- endblock in_prompt %}
{% block empty_in_prompt -%}
<div class="prompt input_prompt">
</div>
{%- endblock empty_in_prompt %}
{#
output_prompt doesn't do anything in HTML,
because there is a prompt div in each output area (see output block)
#}
{% block output_prompt %}
{% endblock output_prompt %}
{% block input %}
<div class="inner_cell">
<div class="input_area">
{{ cell.input | highlight2html(language=resources.get('language'), metadata=cell.metadata) }}
</div>
</div>
{%- endblock input %}
{% block output %}
<div class="output_area">
{%- if output.output_type == 'pyout' -%}
<div class="prompt output_prompt">
Out[{{ cell.prompt_number }}]:
{%- else -%}
<div class="prompt">
{%- endif -%}
</div>
{{ super() }}
</div>
{% endblock output %}
{% block markdowncell scoped %}
<div class="cell border-box-sizing text_cell rendered">
{{ self.empty_in_prompt() }}
<div class="inner_cell">
<div class="text_cell_render border-box-sizing rendered_html">
{{ cell.source | markdown2html | strip_files_prefix }}
</div>
</div>
</div>
{%- endblock markdowncell %}
{% block headingcell scoped %}
<div class="cell border-box-sizing text_cell rendered">
{{ self.empty_in_prompt() }}
<div class="inner_cell">
<div class="text_cell_render border-box-sizing rendered_html">
{{ ("#" * cell.level + cell.source) | replace('\n', ' ') | markdown2html | strip_files_prefix | add_anchor }}
</div>
</div>
</div>
{% endblock headingcell %}
{% block unknowncell scoped %}
unknown type {{ cell.type }}
{% endblock unknowncell %}
{% block pyout -%}
{%- set extra_class="output_pyout" -%}
{% block data_priority scoped %}
{{ super() }}
{% endblock %}
{%- set extra_class="" -%}
{%- endblock pyout %}
{% block stream_stdout -%}
<div class="output_subarea output_stream output_stdout output_text">
<pre>
{{- output.text | ansi2html -}}
</pre>
</div>
{%- endblock stream_stdout %}
{% block stream_stderr -%}
<div class="output_subarea output_stream output_stderr output_text">
<pre>
{{- output.text | ansi2html -}}
</pre>
</div>
{%- endblock stream_stderr %}
{% block data_svg scoped -%}
<div class="output_svg output_subarea {{extra_class}}">
{%- if output.svg_filename %}
<img src="{{output.svg_filename | posix_path}}"
{%- else %}
{{ output.svg }}
{%- endif %}
</div>
{%- endblock data_svg %}
{% block data_html scoped -%}
<div class="output_html rendered_html output_subarea {{extra_class}}">
{{ output.html }}
</div>
{%- endblock data_html %}
{% block data_png scoped %}
<div class="output_png output_subarea {{extra_class}}">
{%- if output.png_filename %}
<img src="{{output.png_filename | posix_path}}"
{%- else %}
<img src="data:image/png;base64,{{ output.png }}"
{%- endif %}
{%- if 'metadata' in output and 'width' in output.metadata.get('png', {}) %}
width={{output.metadata['png']['width']}}
{%- endif %}
{%- if 'metadata' in output and 'height' in output.metadata.get('png', {}) %}
height={{output.metadata['png']['height']}}
{%- endif %}
>
</div>
{%- endblock data_png %}
{% block data_jpg scoped %}
<div class="output_jpeg output_subarea {{extra_class}}">
{%- if output.jpeg_filename %}
<img src="{{output.jpeg_filename | posix_path}}"
{%- else %}
<img src="data:image/jpeg;base64,{{ output.jpeg }}"
{%- endif %}
{%- if 'metadata' in output and 'width' in output.metadata.get('jpeg', {}) %}
width={{output.metadata['jpeg']['width']}}
{%- endif %}
{%- if 'metadata' in output and 'height' in output.metadata.get('jpeg', {}) %}
height={{output.metadata['jpeg']['height']}}
{%- endif %}
>
</div>
{%- endblock data_jpg %}
{% block data_latex scoped %}
<div class="output_latex output_subarea {{extra_class}}">
{{ output.latex }}
</div>
{%- endblock data_latex %}
{% block pyerr -%}
<div class="output_subarea output_text output_pyerr">
<pre>
{{- super() -}}
</pre>
</div>
{%- endblock pyerr %}
{%- block traceback_line %}
{{ line | ansi2html }}
{%- endblock traceback_line %}
{%- block data_text scoped %}
<div class="output_text output_subarea {{extra_class}}">
<pre>
{{- output.text | ansi2html -}}
</pre>
</div>
{%- endblock -%}
{%- block data_javascript scoped %}
<div class="output_subarea output_javascript {{extra_class}}">
<script type="text/javascript">
{{ output.javascript }}
</script>
</div>
{%- endblock -%}