83 lines
2.1 KiB
Python
83 lines
2.1 KiB
Python
'''
|
|
Compatibility module for Python 2.7 and >= 3.4
|
|
==============================================
|
|
|
|
This module provides a set of utility types and functions for optimization and
|
|
to aid in writing Python 2/3 compatible code.
|
|
'''
|
|
|
|
__all__ = ('PY2', 'clock', 'string_types', 'queue', 'iterkeys',
|
|
'itervalues', 'iteritems', 'isclose')
|
|
|
|
import sys
|
|
import time
|
|
from math import isinf, fabs
|
|
try:
|
|
import queue
|
|
except ImportError:
|
|
import Queue as queue
|
|
try:
|
|
from math import isclose
|
|
except ImportError:
|
|
isclose = None
|
|
|
|
PY2 = False
|
|
'''False, because we don't support Python 2 anymore.'''
|
|
|
|
clock = None
|
|
'''A clock with the highest available resolution on your current Operating
|
|
System.'''
|
|
|
|
string_types = str
|
|
'''A utility type for detecting string in a Python 2/3 friendly way. For
|
|
example:
|
|
|
|
.. code-block:: python
|
|
|
|
if isinstance(s, string_types):
|
|
print("It's a string or unicode type")
|
|
else:
|
|
print("It's something else.")
|
|
'''
|
|
|
|
text_type = str
|
|
|
|
#: unichr is just chr in py3, since all strings are unicode
|
|
unichr = chr
|
|
|
|
iterkeys = lambda d: iter(d.keys())
|
|
itervalues = lambda d: iter(d.values())
|
|
iteritems = lambda d: iter(d.items())
|
|
|
|
|
|
clock = time.perf_counter
|
|
|
|
|
|
def _isclose(a, b, rel_tol=1e-9, abs_tol=0.0):
|
|
'''Measures whether two floats are "close" to each other. Identical to
|
|
https://docs.python.org/3.6/library/math.html#math.isclose, for older
|
|
versions of python.
|
|
'''
|
|
|
|
if a == b: # short-circuit exact equality
|
|
return True
|
|
|
|
if rel_tol < 0.0 or abs_tol < 0.0:
|
|
raise ValueError('error tolerances must be non-negative')
|
|
|
|
# use cmath so it will work with complex or float
|
|
if isinf(abs(a)) or isinf(abs(b)):
|
|
# This includes the case of two infinities of opposite sign, or
|
|
# one infinity and one finite number. Two infinities of opposite sign
|
|
# would otherwise have an infinite relative tolerance.
|
|
return False
|
|
diff = fabs(b - a)
|
|
|
|
return (((diff <= fabs(rel_tol * b)) or
|
|
(diff <= fabs(rel_tol * a))) or
|
|
(diff <= abs_tol))
|
|
|
|
|
|
if isclose is None:
|
|
isclose = _isclose
|