/timm's /charming /python /tricks

base.py

Download base.py.
Read more on How to be Charming (in Python).

01: import sys
02: sys.dont_write_bytecode=True # no .pyc files
03: import random
04: 
05: #---- Cool Classes ----------------------------
06: 
07: class Charmed:
08:   "Our objects are charming."
09:   def __repr__(i):
10:     """
11:     This Charmed object knows how to print
12:     all their slots, except for the private ones
13:     (those that start with "_").
14:     """
15:     args = []
16:     for key,val in vars(i).items(): 
17:       if key[0] != "_":
18:         args += ['%s=%s'% (key,val)]
19:     what = i.__class__.__name__
20:     return '%s(%s)' % (what, ', '.join(args)) 
21: 
22: class Thing(Charmed):
23:   """Norvig's shortcut for creating objects that 
24:   that holds data in several fields."""
25:   def __init__(self, **entries): 
26:     self.__dict__.update(entries)
27: 
28: class Sample(Charmed):
29:   "Keep a random sample of stuff seen so far."
30:   def __init__(i,size=64):
31:     i._cache, i.size, i.n = [],size, 0.0
32:     i._ordered=False
33:   def sorted(i):
34:     if not i._ordered:
35:       i._cache = sorted(i._cache)
36:       i._ordered=True
37:     return i._cache
38:   def seen(i,x):
39:     i.n += 1
40:     if len(i._cache) < i.size : 
41:       i._cache += [x]
42:       i._ordered=False
43:     else:
44:       if random.random() <= i.size/i.n:
45:         i._cache[int(random.random()*i.size)] = x
46:         i._ordered=False
47: 

This file is part of Timm's charming Python tricks.
© 2014, Tim Menzies: tim.menzies@gmail.com, http://menzies.us.

Timm's charming Python tricks are free software: you can redistribute it and/or modify it under the terms of the GNU Lesser Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Timm's charming Python tricks are 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 General Public License for more details.

You should have received a copy of the GNU Lesser Public License along with Foobar. If not, see http://www.gnu.org/licenses.