1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
|
from __future__ import unicode_literals
import inspect
import os
import signal
import sys
import threading
import weakref
from wcwidth import wcwidth
from six.moves import range
__all__ = (
'Event',
'DummyContext',
'get_cwidth',
'suspend_to_background_supported',
'is_conemu_ansi',
'is_windows',
'in_main_thread',
'take_using_weights',
'test_callable_args',
)
class Event(object):
"""
Simple event to which event handlers can be attached. For instance::
class Cls:
def __init__(self):
# Define event. The first parameter is the sender.
self.event = Event(self)
obj = Cls()
def handler(sender):
pass
# Add event handler by using the += operator.
obj.event += handler
# Fire event.
obj.event()
"""
def __init__(self, sender, handler=None):
self.sender = sender
self._handlers = []
if handler is not None:
self += handler
def __call__(self):
" Fire event. "
for handler in self._handlers:
handler(self.sender)
def fire(self):
" Alias for just calling the event. "
self()
def __iadd__(self, handler):
"""
Add another handler to this callback.
(Handler should be a callable that takes exactly one parameter: the
sender object.)
"""
# Test handler.
assert callable(handler)
if not test_callable_args(handler, [None]):
raise TypeError("%r doesn't take exactly one argument." % handler)
# Add to list of event handlers.
self._handlers.append(handler)
return self
def __isub__(self, handler):
"""
Remove a handler from this callback.
"""
self._handlers.remove(handler)
return self
# Cache of signatures. Improves the performance of `test_callable_args`.
_signatures_cache = weakref.WeakKeyDictionary()
def test_callable_args(func, args):
"""
Return True when this function can be called with the given arguments.
"""
assert isinstance(args, (list, tuple))
signature = getattr(inspect, 'signature', None)
if signature is not None:
# For Python 3, use inspect.signature.
try:
sig = _signatures_cache[func]
except KeyError:
sig = signature(func)
_signatures_cache[func] = sig
try:
sig.bind(*args)
except TypeError:
return False
else:
return True
else:
# For older Python versions, fall back to using getargspec.
spec = inspect.getargspec(func)
# Drop the 'self'
def drop_self(spec):
args, varargs, varkw, defaults = spec
if args[0:1] == ['self']:
args = args[1:]
return inspect.ArgSpec(args, varargs, varkw, defaults)
spec = drop_self(spec)
# When taking *args, always return True.
if spec.varargs is not None:
return True
# Test whether the given amount of args is between the min and max
# accepted argument counts.
return len(spec.args) - len(spec.defaults or []) <= len(args) <= len(spec.args)
class DummyContext(object):
"""
(contextlib.nested is not available on Py3)
"""
def __enter__(self):
pass
def __exit__(self, *a):
pass
class _CharSizesCache(dict):
"""
Cache for wcwidth sizes.
"""
def __missing__(self, string):
# Note: We use the `max(0, ...` because some non printable control
# characters, like e.g. Ctrl-underscore get a -1 wcwidth value.
# It can be possible that these characters end up in the input
# text.
if len(string) == 1:
result = max(0, wcwidth(string))
else:
result = sum(max(0, wcwidth(c)) for c in string)
# Cache for short strings.
# (It's hard to tell what we can consider short...)
if len(string) < 256:
self[string] = result
return result
_CHAR_SIZES_CACHE = _CharSizesCache()
def get_cwidth(string):
"""
Return width of a string. Wrapper around ``wcwidth``.
"""
return _CHAR_SIZES_CACHE[string]
def suspend_to_background_supported():
"""
Returns `True` when the Python implementation supports
suspend-to-background. This is typically `False' on Windows systems.
"""
return hasattr(signal, 'SIGTSTP')
def is_windows():
"""
True when we are using Windows.
"""
return sys.platform.startswith('win') # E.g. 'win32', not 'darwin' or 'linux2'
def is_conemu_ansi():
"""
True when the ConEmu Windows console is used.
"""
return is_windows() and os.environ.get('ConEmuANSI', 'OFF') == 'ON'
def in_main_thread():
"""
True when the current thread is the main thread.
"""
return threading.current_thread().__class__.__name__ == '_MainThread'
def take_using_weights(items, weights):
"""
Generator that keeps yielding items from the items list, in proportion to
their weight. For instance::
# Getting the first 70 items from this generator should have yielded 10
# times A, 20 times B and 40 times C, all distributed equally..
take_using_weights(['A', 'B', 'C'], [5, 10, 20])
:param items: List of items to take from.
:param weights: Integers representing the weight. (Numbers have to be
integers, not floats.)
"""
assert isinstance(items, list)
assert isinstance(weights, list)
assert all(isinstance(i, int) for i in weights)
assert len(items) == len(weights)
assert len(items) > 0
already_taken = [0 for i in items]
item_count = len(items)
max_weight = max(weights)
i = 0
while True:
# Each iteration of this loop, we fill up until by (total_weight/max_weight).
adding = True
while adding:
adding = False
for item_i, item, weight in zip(range(item_count), items, weights):
if already_taken[item_i] < i * weight / float(max_weight):
yield item
already_taken[item_i] += 1
adding = True
i += 1
|
