Adding interact.py.

IPython/html/widgets/interact.py

@@ -0,0 +1,123 @@
+"""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 IPython.html.widgets import (Widget, StringWidget,
+    FloatRangeWidget, IntRangeWidget, BoolWidget, SelectionWidget,
+    ContainerWidget)
+from IPython.display import display, clear_output
+from IPython.utils.py3compat import string_types, unicode_type
+
+#-----------------------------------------------------------------------------
+# Classes and Functions
+#-----------------------------------------------------------------------------
+
+
+def _matches(o, pattern):
+    if not len(o) == len(pattern):
+        return False
+    comps = zip(o,pattern)
+    return all(isinstance(obj,kind) for obj,kind in comps)
+
+
+def _min_max_value(o):
+    min = o[0]
+    max = o[1]
+    if not max > min:
+        raise ValueError('max must be greater than min: (min={0}, max={1})'.format(min, max))
+    value = min + abs(o[0]-o[1])/2
+    return min, max, value
+
+def _widget_abbrev(o):
+    if isinstance(o, string_types):
+        return StringWidget(value=unicode_type(o))
+    elif isinstance(o, dict):
+        values = [unicode_type(k) for k in o]
+        w = SelectionWidget(value=values[0], values=values)
+        w.actual_values = o
+        return w
+    # Special case float and int == 0.0
+    # get_range(value):
+    elif isinstance(o, bool):
+        return BoolWidget(value=o)
+    elif isinstance(o, float):
+        return FloatRangeWidget(value=o, min=-o, max=3.0*o)
+    elif isinstance(o, int):
+        return IntRangeWidget(value=o, min=-o, max=3*o)
+    if isinstance(o, (list, tuple)):
+        if _matches(o, (int, int)):
+            min, max, value = _min_max_value(o)
+            return IntRangeWidget(value=int(value), min=min, max=max)
+        elif _matches(o, (int, int, int)):
+            min, max, value = _min_max_value(o)
+            return IntRangeWidget(value=int(value), min=min, max=max, step=o[2])
+        elif _matches(o, (float, float)):
+            min, max, value = _min_max_value(o)
+            return FloatRangeWidget(value=value, min=min, max=max)
+        elif _matches(o, (float, float, float)):
+            min, max, value = _min_max_value(o)
+            return FloatRangeWidget(value=value, min=min, max=max, step=o[2])
+        elif _matches(o, (float, float, int)):
+            min, max, value = _min_max_value(o)
+            return FloatRangeWidget(value=value, min=min, max=max, step=float(o[2]))
+        elif all(isinstance(x, string_types) for x in o):
+            return SelectionWidget(value=unicode_type(o[0]),
+                                   values=[unicode_type(k) for k in o])
+
+
+def interactive(f, **kwargs):
+    """Interact with a function using widgets."""
+    
+    co = kwargs.pop('clear_output', True)
+    # First convert all args to Widget instances
+    widgets = []
+    container = ContainerWidget()
+    container.result = None
+    container.arguments = dict()
+    for key, value in kwargs.items():
+        if isinstance(value, Widget):
+            widget = value
+        else:
+            widget = _widget_abbrev(value)
+            if widget is None:
+                raise ValueError("Object cannot be transformed to a Widget")
+        widgets.append((key,widget))
+        widget.parent = container
+    widgets.sort(key=lambda e: e[1].__class__.__name__)
+ 
+    # Build the callback
+    def call_f(name, old, new):
+        actual_kwargs = {}
+        for key, widget in widgets:
+            value = widget.value
+            if hasattr(widget, 'actual_values'):
+                value = widget.actual_values[value]
+            container.arguments[key] = value
+            actual_kwargs[key] = value
+        if co:
+            clear_output(wait=True)
+        container.result = f(**actual_kwargs)
+
+    # Wire up the widgets
+    for key, widget in widgets:
+        widget.on_trait_change(call_f, 'value')
+        widget.description = key
+
+    container.on_displayed(lambda : call_f(None, None, None))
+
+    return container
+
+def interact(f, **kwargs):
+    w = interactive(f, **kwargs)
+    display(w)