forked from fluentpython/example-code
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathvector_v5.py
More file actions
288 lines (225 loc) · 7.02 KB
/
vector_v5.py
File metadata and controls
288 lines (225 loc) · 7.02 KB
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
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
# BEGIN VECTOR_V5
"""
A multi-dimensional ``Vector`` class, take 5
A ``Vector`` is built from an iterable of numbers::
>>> Vector([3.1, 4.2])
Vector([3.1, 4.2])
>>> Vector((3, 4, 5))
Vector([3.0, 4.0, 5.0])
>>> Vector(range(10))
Vector([0.0, 1.0, 2.0, 3.0, 4.0, ...])
Tests with 2-dimensions (same results as ``vector2d_v1.py``)::
>>> v1 = Vector([3, 4])
>>> x, y = v1
>>> x, y
(3.0, 4.0)
>>> v1
Vector([3.0, 4.0])
>>> v1_clone = eval(repr(v1))
>>> v1 == v1_clone
True
>>> print(v1)
(3.0, 4.0)
>>> octets = bytes(v1)
>>> octets
b'd\\x00\\x00\\x00\\x00\\x00\\x00\\x08@\\x00\\x00\\x00\\x00\\x00\\x00\\x10@'
>>> abs(v1)
5.0
>>> bool(v1), bool(Vector([0, 0]))
(True, False)
Test of ``.frombytes()`` class method:
>>> v1_clone = Vector.frombytes(bytes(v1))
>>> v1_clone
Vector([3.0, 4.0])
>>> v1 == v1_clone
True
Tests with 3-dimensions::
>>> v1 = Vector([3, 4, 5])
>>> x, y, z = v1
>>> x, y, z
(3.0, 4.0, 5.0)
>>> v1
Vector([3.0, 4.0, 5.0])
>>> v1_clone = eval(repr(v1))
>>> v1 == v1_clone
True
>>> print(v1)
(3.0, 4.0, 5.0)
>>> abs(v1) # doctest:+ELLIPSIS
7.071067811...
>>> bool(v1), bool(Vector([0, 0, 0]))
(True, False)
Tests with many dimensions::
>>> v7 = Vector(range(7))
>>> v7
Vector([0.0, 1.0, 2.0, 3.0, 4.0, ...])
>>> abs(v7) # doctest:+ELLIPSIS
9.53939201...
Test of ``.__bytes__`` and ``.frombytes()`` methods::
>>> v1 = Vector([3, 4, 5])
>>> v1_clone = Vector.frombytes(bytes(v1))
>>> v1_clone
Vector([3.0, 4.0, 5.0])
>>> v1 == v1_clone
True
Tests of sequence behavior::
>>> v1 = Vector([3, 4, 5])
>>> len(v1)
3
>>> v1[0], v1[len(v1)-1], v1[-1]
(3.0, 5.0, 5.0)
Test of slicing::
>>> v7 = Vector(range(7))
>>> v7[-1]
6.0
>>> v7[1:4]
Vector([1.0, 2.0, 3.0])
>>> v7[-1:]
Vector([6.0])
>>> v7[1,2]
Traceback (most recent call last):
...
TypeError: Vector indices must be integers
Tests of dynamic attribute access::
>>> v7 = Vector(range(10))
>>> v7.x
0.0
>>> v7.y, v7.z, v7.t
(1.0, 2.0, 3.0)
Dynamic attribute lookup failures::
>>> v7.k
Traceback (most recent call last):
...
AttributeError: 'Vector' object has no attribute 'k'
>>> v3 = Vector(range(3))
>>> v3.t
Traceback (most recent call last):
...
AttributeError: 'Vector' object has no attribute 't'
>>> v3.spam
Traceback (most recent call last):
...
AttributeError: 'Vector' object has no attribute 'spam'
Tests of hashing::
>>> v1 = Vector([3, 4])
>>> v2 = Vector([3.1, 4.2])
>>> v3 = Vector([3, 4, 5])
>>> v6 = Vector(range(6))
>>> hash(v1), hash(v3), hash(v6)
(7, 2, 1)
Most hash values of non-integers vary from a 32-bit to 64-bit CPython build::
>>> import sys
>>> hash(v2) == (384307168202284039 if sys.maxsize > 2**32 else 357915986)
True
Tests of ``format()`` with Cartesian coordinates in 2D::
>>> v1 = Vector([3, 4])
>>> format(v1)
'(3.0, 4.0)'
>>> format(v1, '.2f')
'(3.00, 4.00)'
>>> format(v1, '.3e')
'(3.000e+00, 4.000e+00)'
Tests of ``format()`` with Cartesian coordinates in 3D and 7D::
>>> v3 = Vector([3, 4, 5])
>>> format(v3)
'(3.0, 4.0, 5.0)'
>>> format(Vector(range(7)))
'(0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0)'
Tests of ``format()`` with spherical coordinates in 2D, 3D and 4D::
>>> format(Vector([1, 1]), 'h') # doctest:+ELLIPSIS
'<1.414213..., 0.785398...>'
>>> format(Vector([1, 1]), '.3eh')
'<1.414e+00, 7.854e-01>'
>>> format(Vector([1, 1]), '0.5fh')
'<1.41421, 0.78540>'
>>> format(Vector([1, 1, 1]), 'h') # doctest:+ELLIPSIS
'<1.73205..., 0.95531..., 0.78539...>'
>>> format(Vector([2, 2, 2]), '.3eh')
'<3.464e+00, 9.553e-01, 7.854e-01>'
>>> format(Vector([0, 0, 0]), '0.5fh')
'<0.00000, 0.00000, 0.00000>'
>>> format(Vector([-1, -1, -1, -1]), 'h') # doctest:+ELLIPSIS
'<2.0, 2.09439..., 2.18627..., 3.92699...>'
>>> format(Vector([2, 2, 2, 2]), '.3eh')
'<4.000e+00, 1.047e+00, 9.553e-01, 7.854e-01>'
>>> format(Vector([0, 1, 0, 0]), '0.5fh')
'<1.00000, 1.57080, 0.00000, 0.00000>'
"""
from array import array
import reprlib
import math
import numbers
import functools
import operator
import itertools # <1>
class Vector:
typecode = 'd'
def __init__(self, components):
self._components = array(self.typecode, components)
def __iter__(self):
return iter(self._components)
def __repr__(self):
components = reprlib.repr(self._components)
components = components[components.find('['):-1]
return 'Vector({})'.format(components)
def __str__(self):
return str(tuple(self))
def __bytes__(self):
return (bytes([ord(self.typecode)]) +
bytes(self._components))
def __eq__(self, other):
return (len(self) == len(other) and
all(a == b for a, b in zip(self, other)))
def __hash__(self):
hashes = (hash(x) for x in self)
return functools.reduce(operator.xor, hashes, 0)
def __abs__(self):
return math.sqrt(sum(x * x for x in self))
def __bool__(self):
return bool(abs(self))
def __len__(self):
return len(self._components)
def __getitem__(self, index):
cls = type(self)
if isinstance(index, slice):
return cls(self._components[index])
elif isinstance(index, numbers.Integral):
return self._components[index]
else:
msg = '{.__name__} indices must be integers'
raise TypeError(msg.format(cls))
shortcut_names = 'xyzt'
def __getattr__(self, name):
cls = type(self)
if len(name) == 1:
pos = cls.shortcut_names.find(name)
if 0 <= pos < len(self._components):
return self._components[pos]
msg = '{.__name__!r} object has no attribute {!r}'
raise AttributeError(msg.format(cls, name))
def angle(self, n): # <2>
r = math.sqrt(sum(x * x for x in self[n:]))
a = math.atan2(r, self[n-1])
if (n == len(self) - 1) and (self[-1] < 0):
return math.pi * 2 - a
else:
return a
def angles(self): # <3>
return (self.angle(n) for n in range(1, len(self)))
def __format__(self, fmt_spec=''):
if fmt_spec.endswith('h'): # hyperspherical coordinates
fmt_spec = fmt_spec[:-1]
coords = itertools.chain([abs(self)],
self.angles()) # <4>
outer_fmt = '<{}>' # <5>
else:
coords = self
outer_fmt = '({})' # <6>
components = (format(c, fmt_spec) for c in coords) # <7>
return outer_fmt.format(', '.join(components)) # <8>
@classmethod
def frombytes(cls, octets):
typecode = chr(octets[0])
memv = memoryview(octets[1:]).cast(typecode)
return cls(memv)
# END VECTOR_V5