Only set widget description in interact if it does not already exist

IPython/html/widgets/interaction.py

@@ -1,256 +1,257
 """Interact with functions using widgets."""
 
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, 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
 
 try:  # Python >= 3.3
     from inspect import signature, Parameter
 except ImportError:
     from IPython.utils.signatures import signature, Parameter
 from inspect import getcallargs
 
 from IPython.core.getipython import get_ipython
 from IPython.html.widgets import (Widget, TextWidget,
     FloatSliderWidget, IntSliderWidget, CheckboxWidget, DropdownWidget,
     ContainerWidget, DOMWidget)
 from IPython.display import display, clear_output
 from IPython.utils.py3compat import string_types, unicode_type
 from IPython.utils.traitlets import HasTraits, Any, Unicode
 
 empty = Parameter.empty
 
 #-----------------------------------------------------------------------------
 # Classes and Functions
 #-----------------------------------------------------------------------------
 
 
 def _matches(o, pattern):
     """Match a pattern of types in a sequence."""
     if not len(o) == len(pattern):
         return False
     comps = zip(o,pattern)
     return all(isinstance(obj,kind) for obj,kind in comps)
 
 
 def _get_min_max_value(min, max, value=None, step=None):
     """Return min, max, value given input values with possible None."""
     if value is None:
         if not max > min:
             raise ValueError('max must be greater than min: (min={0}, max={1})'.format(min, max))
         value = min + abs(min-max)/2
         value = type(min)(value)
     elif min is None and max is None:
         if value == 0.0:
             min, max, value = 0.0, 1.0, 0.5
         elif value == 0:
             min, max, value = 0, 1, 0
         elif isinstance(value, (int, float)):
             min, max = (-value, 3*value) if value > 0 else (3*value, -value)
         else:
             raise TypeError('expected a number, got: %r' % value)
     else:
         raise ValueError('unable to infer range, value from: ({0}, {1}, {2})'.format(min, max, value))
     if step is not None:
         # ensure value is on a step
         r = (value - min) % step
         value = value - r
     return min, max, value
 
 def _widget_abbrev_single_value(o):
     """Make widgets from single values, which can be used as parameter defaults."""
     if isinstance(o, string_types):
         return TextWidget(value=unicode_type(o))
     elif isinstance(o, dict):
         return DropdownWidget(values=o)
     elif isinstance(o, bool):
         return CheckboxWidget(value=o)
     elif isinstance(o, float):
         min, max, value = _get_min_max_value(None, None, o)
         return FloatSliderWidget(value=o, min=min, max=max)
     elif isinstance(o, int):
         min, max, value = _get_min_max_value(None, None, o)
         return IntSliderWidget(value=o, min=min, max=max)
     else:
         return None
 
 def _widget_abbrev(o):
     """Make widgets from abbreviations: single values, lists or tuples."""
     float_or_int = (float, int)
     if isinstance(o, (list, tuple)):
         if o and all(isinstance(x, string_types) for x in o):
             return DropdownWidget(values=[unicode_type(k) for k in o])
         elif _matches(o, (float_or_int, float_or_int)):
             min, max, value = _get_min_max_value(o[0], o[1])
             if all(isinstance(_, int) for _ in o):
                 cls = IntSliderWidget
             else:
                 cls = FloatSliderWidget
             return cls(value=value, min=min, max=max)
         elif _matches(o, (float_or_int, float_or_int, float_or_int)):
             step = o[2]
             if step <= 0:
                 raise ValueError("step must be >= 0, not %r" % step)
             min, max, value = _get_min_max_value(o[0], o[1], step=step)
             if all(isinstance(_, int) for _ in o):
                 cls = IntSliderWidget
             else:
                 cls = FloatSliderWidget
             return cls(value=value, min=min, max=max, step=step)
     else:
         return _widget_abbrev_single_value(o)
 
 def _widget_from_abbrev(abbrev, default=empty):
     """Build a Widget instance given an abbreviation or Widget."""
     if isinstance(abbrev, Widget) or isinstance(abbrev, fixed):
         return abbrev
     
     widget = _widget_abbrev(abbrev)
     if default is not empty and isinstance(abbrev, (list, tuple, dict)):
         # if it's not a single-value abbreviation,
         # set the initial value from the default
         try:
             widget.value = default
         except Exception:
             # ignore failure to set default
             pass
     if widget is None:
         raise ValueError("%r cannot be transformed to a Widget" % (abbrev,))
     return widget
 
 def _yield_abbreviations_for_parameter(param, kwargs):
     """Get an abbreviation for a function parameter."""
     name = param.name
     kind = param.kind
     ann = param.annotation
     default = param.default
     not_found = (name, empty, empty)
     if kind in (Parameter.POSITIONAL_OR_KEYWORD, Parameter.KEYWORD_ONLY):
         if name in kwargs:
             value = kwargs.pop(name)
         elif ann is not empty:
             value = ann
         elif default is not empty:
             value = default
         else:
             yield not_found
         yield (name, value, default)
     elif kind == Parameter.VAR_KEYWORD:
         # In this case name=kwargs and we yield the items in kwargs with their keys.
         for k, v in kwargs.copy().items():
             kwargs.pop(k)
             yield k, v, empty
 
 def _find_abbreviations(f, kwargs):
     """Find the abbreviations for a function and kwargs passed to interact."""
     new_kwargs = []
     for param in signature(f).parameters.values():
         for name, value, default in _yield_abbreviations_for_parameter(param, kwargs):
             if value is empty:
                 raise ValueError('cannot find widget or abbreviation for argument: {!r}'.format(name))
             new_kwargs.append((name, value, default))
     return new_kwargs
 
 def _widgets_from_abbreviations(seq):
     """Given a sequence of (name, abbrev) tuples, return a sequence of Widgets."""
     result = []
     for name, abbrev, default in seq:
         widget = _widget_from_abbrev(abbrev, default)
+        if not widget.description:
         widget.description = name
         result.append(widget)
     return result
 
 def interactive(__interact_f, **kwargs):
     """Build a group of widgets to interact with a function."""
     f = __interact_f
     co = kwargs.pop('clear_output', True)
     kwargs_widgets = []
     container = ContainerWidget()
     container.result = None
     container.args = []
     container.kwargs = dict()
     kwargs = kwargs.copy()
 
     new_kwargs = _find_abbreviations(f, kwargs)
     # Before we proceed, let's make sure that the user has passed a set of args+kwargs
     # that will lead to a valid call of the function. This protects against unspecified
     # and doubly-specified arguments.
     getcallargs(f, **{n:v for n,v,_ in new_kwargs})
     # Now build the widgets from the abbreviations.
     kwargs_widgets.extend(_widgets_from_abbreviations(new_kwargs))
 
     # This has to be done as an assignment, not using container.children.append,
     # so that traitlets notices the update. We skip any objects (such as fixed) that
     # are not DOMWidgets.
     c = [w for w in kwargs_widgets if isinstance(w, DOMWidget)]
     container.children = c
 
     # Build the callback
     def call_f(name, old, new):
         container.kwargs = {}
         for widget in kwargs_widgets:
             value = widget.value
             container.kwargs[widget.description] = value
         if co:
             clear_output(wait=True)
         try:
             container.result = f(**container.kwargs)
         except Exception as e:
             ip = get_ipython()
             if ip is None:
                 container.log.warn("Exception in interact callback: %s", e, exc_info=True)
             else:
                 ip.showtraceback()
 
     # Wire up the widgets
     for widget in kwargs_widgets:
         widget.on_trait_change(call_f, 'value')
 
     container.on_displayed(lambda _: call_f(None, None, None))
 
     return container
 
 def interact(__interact_f=None, **kwargs):
     """interact(f, **kwargs)
     
     Interact with a function using widgets."""
     # positional arg support in: https://gist.github.com/8851331
     if __interact_f is not None:
         # This branch handles the cases:
         # 1. interact(f, **kwargs)
         # 2. @interact
         #    def f(*args, **kwargs):
         #        ...
         f = __interact_f
         w = interactive(f, **kwargs)
         f.widget = w
         display(w)
         return f
     else:
         # This branch handles the case:
         # @interact(a=30, b=40)
         # def f(*args, **kwargs):
         #     ...
         def dec(f):
             w = interactive(f, **kwargs)
             f.widget = w
             display(w)
             return f
         return dec
 
 class fixed(HasTraits):
     """A pseudo-widget whose value is fixed and never synced to the client."""
     value = Any(help="Any Python object")
     description = Unicode('', help="Any Python object")
     def __init__(self, value, **kwargs):
         super(fixed, self).__init__(value=value, **kwargs)

examples/Interactive Widgets/Using Interact.ipynb

@@ -1,170 +1,170
 {
  "metadata": {
   "name": "",
-  "signature": "sha256:d75ab1c53fa3389eeac78ecf8e89beb52871950f296aad25776699b6d6125037"
+  "signature": "sha256:3f30c6e839ac39f890da34a2af6bf50bf0d99ea32f7aadc043f3e31f619e4bc9"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
  "worksheets": [
   {
    "cells": [
     {
      "cell_type": "heading",
      "level": 1,
      "metadata": {},
      "source": [
       "Interact"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "The `interact` function provides a high-level interface for creating user interface controls to use in exploring code and data interactively."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "from IPython.html.widgets import interact, interactive, fixed\n",
       "from IPython.html import widgets\n",
       "from IPython.display import clear_output, display, HTML"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
      "prompt_number": 1
     },
     {
      "cell_type": "heading",
      "level": 2,
      "metadata": {},
      "source": [
       "Basic interact"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "Here is a simple function that displays its arguments as an HTML table:"
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "def show_args(**kwargs):\n",
       "    s = '<h3>Arguments:</h3><table>\\n'\n",
       "    for k,v in kwargs.items():\n",
       "        s += '<tr><td>{0}</td><td>{1}</td></tr>\\n'.format(k,v)\n",
       "    s += '</table>'\n",
       "    display(HTML(s))"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
      "prompt_number": 2
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "show_args(a=10, b='Hi There', c=True)"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "html": [
         "<h3>Arguments:</h3><table>\n",
         "<tr><td>a</td><td>10</td></tr>\n",
         "<tr><td>c</td><td>True</td></tr>\n",
         "<tr><td>b</td><td>Hi There</td></tr>\n",
         "</table>"
        ],
        "metadata": {},
        "output_type": "display_data",
        "text": [
-        "<IPython.core.display.HTML at 0x10efc0d50>"
+        "<IPython.core.display.HTML object>"
        ]
       }
      ],
      "prompt_number": 3
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "Let's use this function to explore how `interact` works."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "i = interact(show_args,\n",
       "         Temp=(0,10),\n",
       "         Current=(0.,10.,0.01),\n",
       "         z=True,\n",
       "         Text=u'Type here!',\n",
       "         #Algorithm=['This','That','Other'],\n",
-      "         a=widgets.FloatSliderWidget(min=-10.0, max=10.0, step=0.1, value=5.0)\n",
+      "         a=widgets.FloatSliderWidget(min=-10.0, max=10.0, step=0.1, value=5.0, description=\"Float (a)\")\n",
       "         )"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "html": [
         "<h3>Arguments:</h3><table>\n",
         "<tr><td>Current</td><td>4.99</td></tr>\n",
         "<tr><td>Text</td><td>Type here!</td></tr>\n",
         "<tr><td>z</td><td>True</td></tr>\n",
-        "<tr><td>a</td><td>5.0</td></tr>\n",
         "<tr><td>Temp</td><td>5</td></tr>\n",
+        "<tr><td>Float (a)</td><td>5.0</td></tr>\n",
         "</table>"
        ],
        "metadata": {},
        "output_type": "display_data",
        "text": [
-        "<IPython.core.display.HTML at 0x10efcca10>"
+        "<IPython.core.display.HTML object>"
        ]
       }
      ],
      "prompt_number": 4
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "i.widget"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "html": [
         "<h3>Arguments:</h3><table>\n",
         "<tr><td>Current</td><td>4.99</td></tr>\n",
         "<tr><td>Text</td><td>Type here!</td></tr>\n",
         "<tr><td>z</td><td>True</td></tr>\n",
-        "<tr><td>a</td><td>5.0</td></tr>\n",
         "<tr><td>Temp</td><td>5</td></tr>\n",
+        "<tr><td>Float (a)</td><td>5.0</td></tr>\n",
         "</table>"
        ],
        "metadata": {},
        "output_type": "display_data",
        "text": [
-        "<IPython.core.display.HTML at 0x10f027050>"
+        "<IPython.core.display.HTML object>"
        ]
       }
      ],
      "prompt_number": 5
     }
    ],
    "metadata": {}
   }
  ]
 }
  No newline at end of file