### comparison env/lib/python3.9/site-packages/boltons/mathutils.py @ 0:4f3585e2f14bdraftdefaulttip

author shellac Mon, 22 Mar 2021 18:12:50 +0000
comparison
equal inserted replaced
-1:000000000000 0:4f3585e2f14b
1 """This module provides useful math functions on top of Python's
2 built-in :mod:`math` module.
3 """
4 from __future__ import division
5
6 from math import ceil as _ceil, floor as _floor
7 import bisect
8 import binascii
9
10
11 def clamp(x, lower=float('-inf'), upper=float('inf')):
12 """Limit a value to a given range.
13
14 Args:
15 x (int or float): Number to be clamped.
16 lower (int or float): Minimum value for x.
17 upper (int or float): Maximum value for x.
18
19 The returned value is guaranteed to be between *lower* and
20 *upper*. Integers, floats, and other comparable types can be
21 mixed.
22
23 >>> clamp(1.0, 0, 5)
24 1.0
25 >>> clamp(-1.0, 0, 5)
26 0
27 >>> clamp(101.0, 0, 5)
28 5
29 >>> clamp(123, upper=5)
30 5
31
32 Similar to `numpy's clip`_ function.
33
34 .. _numpy's clip: http://docs.scipy.org/doc/numpy/reference/generated/numpy.clip.html
35
36 """
37 if upper < lower:
38 raise ValueError('expected upper bound (%r) >= lower bound (%r)'
39 % (upper, lower))
40 return min(max(x, lower), upper)
41
42
43 def ceil(x, options=None):
44 """Return the ceiling of *x*. If *options* is set, return the smallest
45 integer or float from *options* that is greater than or equal to
46 *x*.
47
48 Args:
49 x (int or float): Number to be tested.
50 options (iterable): Optional iterable of arbitrary numbers
51 (ints or floats).
52
53 >>> VALID_CABLE_CSA = [1.5, 2.5, 4, 6, 10, 25, 35, 50]
54 >>> ceil(3.5, options=VALID_CABLE_CSA)
55 4
56 >>> ceil(4, options=VALID_CABLE_CSA)
57 4
58 """
59 if options is None:
60 return _ceil(x)
61 options = sorted(options)
62 i = bisect.bisect_left(options, x)
63 if i == len(options):
64 raise ValueError("no ceil options greater than or equal to: %r" % x)
65 return options[i]
66
67
68 def floor(x, options=None):
69 """Return the floor of *x*. If *options* is set, return the largest
70 integer or float from *options* that is less than or equal to
71 *x*.
72
73 Args:
74 x (int or float): Number to be tested.
75 options (iterable): Optional iterable of arbitrary numbers
76 (ints or floats).
77
78 >>> VALID_CABLE_CSA = [1.5, 2.5, 4, 6, 10, 25, 35, 50]
79 >>> floor(3.5, options=VALID_CABLE_CSA)
80 2.5
81 >>> floor(2.5, options=VALID_CABLE_CSA)
82 2.5
83
84 """
85 if options is None:
86 return _floor(x)
87 options = sorted(options)
88
89 i = bisect.bisect_right(options, x)
90 if not i:
91 raise ValueError("no floor options less than or equal to: %r" % x)
92 return options[i - 1]
93
94
95 try:
96 _int_types = (int, long)
97 bytes = str
98 except NameError:
99 # py3 has no long
100 _int_types = (int,)
101 unicode = str
102
103
104 class Bits(object):
105 '''
106 An immutable bit-string or bit-array object.
108 as well as bitwise masking and shifting operators.
109 Bits also make it easy to convert between many
110 different useful representations:
111
112 * bytes -- good for serializing raw binary data
113 * int -- good for incrementing (e.g. to try all possible values)
114 * list of bools -- good for iterating over or treating as flags
115 * hex/bin string -- good for human readability
116
117 '''
118 __slots__ = ('val', 'len')
119
120 def __init__(self, val=0, len_=None):
121 if type(val) not in _int_types:
122 if type(val) is list:
123 val = ''.join(['1' if e else '0' for e in val])
124 if type(val) is bytes:
125 val = val.decode('ascii')
126 if type(val) is unicode:
127 if len_ is None:
128 len_ = len(val)
129 if val.startswith('0x'):
130 len_ = (len_ - 2) * 4
131 if val.startswith('0x'):
132 val = int(val, 16)
133 else:
134 if val:
135 val = int(val, 2)
136 else:
137 val = 0
138 if type(val) not in _int_types:
139 raise TypeError('initialized with bad type: {0}'.format(type(val).__name__))
140 if val < 0:
141 raise ValueError('Bits cannot represent negative values')
142 if len_ is None:
143 len_ = len('{0:b}'.format(val))
144 if val > 2 ** len_:
145 raise ValueError('value {0} cannot be represented with {1} bits'.format(val, len_))
146 self.val = val # data is stored internally as integer
147 self.len = len_
148
149 def __getitem__(self, k):
150 if type(k) is slice:
151 return Bits(self.as_bin()[k])
152 if type(k) is int:
153 if k >= self.len:
154 raise IndexError(k)
155 return bool((1 << (self.len - k - 1)) & self.val)
156 raise TypeError(type(k))
157
158 def __len__(self):
159 return self.len
160
161 def __eq__(self, other):
162 if type(self) is not type(other):
163 return NotImplemented
164 return self.val == other.val and self.len == other.len
165
166 def __or__(self, other):
167 if type(self) is not type(other):
168 return NotImplemented
169 return Bits(self.val | other.val, max(self.len, other.len))
170
171 def __and__(self, other):
172 if type(self) is not type(other):
173 return NotImplemented
174 return Bits(self.val & other.val, max(self.len, other.len))
175
176 def __lshift__(self, other):
177 return Bits(self.val << other, self.len + other)
178
179 def __rshift__(self, other):
180 return Bits(self.val >> other, self.len - other)
181
182 def __hash__(self):
183 return hash(self.val)
184
185 def as_list(self):
186 return [c == '1' for c in '{0:b}'.format(self.val)]
187
188 def as_bin(self):
189 return '{{0:0{0}b}}'.format(self.len).format(self.val)
190
191 def as_hex(self):
192 # make template to pad out to number of bytes necessary to represent bits
193 tmpl = '%0{0}X'.format(2 * (self.len // 8 + ((self.len % 8) != 0)))
194 ret = tmpl % self.val
195 return ret
196
197 def as_int(self):
198 return self.val
199
200 def as_bytes(self):
201 return binascii.unhexlify(self.as_hex())
202
203 @classmethod
204 def from_list(cls, list_):
205 return cls(list_)
206
207 @classmethod
208 def from_bin(cls, bin):
209 return cls(bin)
210
211 @classmethod
212 def from_hex(cls, hex):
213 if isinstance(hex, bytes):
214 hex = hex.decode('ascii')
215 if not hex.startswith('0x'):
216 hex = '0x' + hex
217 return cls(hex)
218
219 @classmethod
220 def from_int(cls, int_, len_=None):
221 return cls(int_, len_)
222
223 @classmethod
224 def from_bytes(cls, bytes_):
225 return cls.from_hex(binascii.hexlify(bytes_))
226
227 def __repr__(self):
228 cn = self.__class__.__name__
229 return "{0}('{1}')".format(cn, self.as_bin())