This repository was archived by the owner on Dec 2, 2021. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 2.2k
Expand file tree
/
Copy pathvector2d_v3_slots.py
More file actions
158 lines (120 loc) · 3.32 KB
/
vector2d_v3_slots.py
File metadata and controls
158 lines (120 loc) · 3.32 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
"""
A 2-dimensional vector class
>>> v1 = Vector2d(3, 4)
>>> print(v1.x, v1.y)
3.0 4.0
>>> x, y = v1
>>> x, y
(3.0, 4.0)
>>> v1
Vector2d(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(Vector2d(0, 0))
(True, False)
Test of ``.frombytes()`` class method:
>>> v1_clone = Vector2d.frombytes(bytes(v1))
>>> v1_clone
Vector2d(3.0, 4.0)
>>> v1 == v1_clone
True
Tests of ``format()`` with Cartesian coordinates:
>>> format(v1)
'(3.0, 4.0)'
>>> format(v1, '.2f')
'(3.00, 4.00)'
>>> format(v1, '.3e')
'(3.000e+00, 4.000e+00)'
Tests of the ``angle`` method::
>>> Vector2d(0, 0).angle()
0.0
>>> Vector2d(1, 0).angle()
0.0
>>> epsilon = 10**-8
>>> abs(Vector2d(0, 1).angle() - math.pi/2) < epsilon
True
>>> abs(Vector2d(1, 1).angle() - math.pi/4) < epsilon
True
Tests of ``format()`` with polar coordinates:
>>> format(Vector2d(1, 1), 'p') # doctest:+ELLIPSIS
'<1.414213..., 0.785398...>'
>>> format(Vector2d(1, 1), '.3ep')
'<1.414e+00, 7.854e-01>'
>>> format(Vector2d(1, 1), '0.5fp')
'<1.41421, 0.78540>'
Tests of `x` and `y` read-only properties:
>>> v1.x, v1.y
(3.0, 4.0)
>>> v1.x = 123
Traceback (most recent call last):
...
AttributeError: can't set attribute
Tests of hashing:
>>> v1 = Vector2d(3, 4)
>>> v2 = Vector2d(3.1, 4.2)
>>> hash(v1), hash(v2)
(7, 384307168202284039)
>>> len(set([v1, v2]))
2
# END VECTOR2D_V3_DEMO
"""
from array import array
import math
# BEGIN VECTOR2D_V3_SLOTS
class Vector2d:
__slots__ = ('__x', '__y')
typecode = 'd'
# methods follow (omitted in book listing)
# END VECTOR2D_V3_SLOTS
def __init__(self, x, y):
self.__x = float(x)
self.__y = float(y)
@property
def x(self):
return self.__x
@property
def y(self):
return self.__y
def __iter__(self):
return (i for i in (self.x, self.y))
def __repr__(self):
class_name = type(self).__name__
return '{}({!r}, {!r})'.format(class_name, *self)
def __str__(self):
return str(tuple(self))
def __bytes__(self):
return (bytes([ord(self.typecode)]) +
bytes(array(self.typecode, self)))
def __eq__(self, other):
return tuple(self) == tuple(other)
def __hash__(self):
return hash(self.x) ^ hash(self.y)
def __abs__(self):
return math.hypot(self.x, self.y)
def __bool__(self):
return bool(abs(self))
def angle(self):
return math.atan2(self.y, self.x)
def __format__(self, fmt_spec=''):
if fmt_spec.endswith('p'):
fmt_spec = fmt_spec[:-1]
coords = (abs(self), self.angle())
outer_fmt = '<{}, {}>'
else:
coords = self
outer_fmt = '({}, {})'
components = (format(c, fmt_spec) for c in coords)
return outer_fmt.format(*components)
@classmethod
def frombytes(cls, octets):
typecode = chr(octets[0])
memv = memoryview(octets[1:]).cast(typecode)
return cls(*memv)