Add "slides" for Pyvo Feb 2016

2016-02-26-pyvo-brq-cli/.gitignore

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+*.pyc
+last_slide

2016-02-26-pyvo-brq-cli/README

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+
+Slides for Pyvo in Feb 2016, adapted from my EuroPython 2013 talk.
+Install dependencies from requirements.txt, then run `slides.py`.
+
+Content license (slides.yaml): CC-BY-SA 3.0,
+http://creativecommons.org/licenses/by-sa/3.0/
+
+Code license (slides.py): MIT

2016-02-26-pyvo-brq-cli/fib.py

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+#!/usr/bin/python
+#
+# Urwid example fibonacci sequence viewer / unbounded data demo
+#    Copyright (C) 2004-2007  Ian Ward
+#
+#    This library is free software; you can redistribute it and/or
+#    modify it under the terms of the GNU Lesser General Public
+#    License as published by the Free Software Foundation; either
+#    version 2.1 of the License, or (at your option) any later version.
+#
+#    This library is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+#    Lesser General Public License for more details.
+#
+#    You should have received a copy of the GNU Lesser General Public
+#    License along with this library; if not, write to the Free Software
+#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Urwid web site: http://excess.org/urwid/
+
+"""
+Urwid example fibonacci sequence viewer / unbounded data demo
+
+Features:
+- custom list walker class for browsing infinite set
+- custom wrap mode "numeric" for wrapping numbers to right and bottom
+"""
+
+import urwid
+
+class FibonacciWalker(urwid.ListWalker):
+    """ListWalker-compatible class for browsing fibonacci set.
+    
+    positions returned are (value at position-1, value at poistion) tuples.
+    """
+    def __init__(self):
+        self.focus = (0,1)
+        self.numeric_layout = NumericLayout()
+
+    def _get_at_pos(self, pos):
+        """Return a widget and the position passed."""
+        return urwid.Text("%d"%pos[1], layout=self.numeric_layout), pos
+
+    def get_focus(self): 
+        return self._get_at_pos(self.focus)
+
+    def set_focus(self, focus):
+        self.focus = focus
+        self._modified()
+
+    def get_next(self, start_from):
+        a, b = start_from
+        focus = b, a+b
+        return self._get_at_pos(focus)
+
+    def get_prev(self, start_from):
+        a, b = start_from
+        focus = b-a, a
+        return self._get_at_pos(focus)
+
+def main():
+    palette = [
+        ('body','black','dark cyan', 'standout'),
+        ('foot','light gray', 'black'),
+        ('key','light cyan', 'black', 'underline'),
+        ('title', 'white', 'black',),
+        ]
+
+    footer_text = [
+        ('title', "Fibonacci Set Viewer"), "    ",
+        ('key', "UP"), ", ", ('key', "DOWN"), ", ",
+        ('key', "PAGE UP"), " and ", ('key', "PAGE DOWN"),
+        " move view  ",
+        ('key', "Q"), " exits",
+        ]
+
+    def exit_on_q(input):
+        if input in ('q', 'Q'):
+            raise urwid.ExitMainLoop()
+
+    listbox = urwid.ListBox(FibonacciWalker())
+    footer = urwid.AttrMap(urwid.Text(footer_text), 'foot')
+    view = urwid.Frame(urwid.AttrWrap(listbox, 'body'), footer=footer)
+    loop = urwid.MainLoop(view, palette, unhandled_input=exit_on_q)
+    loop.run()
+
+
+class NumericLayout(urwid.TextLayout):
+    """
+    TextLayout class for bottom-right aligned numbers
+    """
+    def layout( self, text, width, align, wrap ):
+        """
+        Return layout structure for right justified numbers.
+        """
+        lt = len(text)
+        r = lt % width # remaining segment not full width wide
+        if r:
+            linestarts = range( r, lt, width )
+            return [
+                # right-align the remaining segment on 1st line
+                [(width-r,None),(r, 0, r)]
+                # fill the rest of the lines
+                ] + [[(width, x, x+width)] for x in linestarts]
+        else:
+            linestarts = range( 0, lt, width )
+            return [[(width, x, x+width)] for x in linestarts]
+
+
+if __name__=="__main__": 
+    main()

2016-02-26-pyvo-brq-cli/requirements.txt

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+urwid
+yaml
+pygments