"""
Utility function to facilitate testing.
"""
from __future__ import division, absolute_import, print_function
import os
import sys
import re
import operator
import warnings
from functools import partial
import shutil
import contextlib
from tempfile import mkdtemp
from .nosetester import import_nose
from numpy.core import float32, empty, arange, array_repr, ndarray
if sys.version_info[0] >= 3:
from io import StringIO
else:
from StringIO import StringIO
__all__ = ['assert_equal', 'assert_almost_equal', 'assert_approx_equal',
'assert_array_equal', 'assert_array_less', 'assert_string_equal',
'assert_array_almost_equal', 'assert_raises', 'build_err_msg',
'decorate_methods', 'jiffies', 'memusage', 'print_assert_equal',
'raises', 'rand', 'rundocs', 'runstring', 'verbose', 'measure',
'assert_', 'assert_array_almost_equal_nulp', 'assert_raises_regex',
'assert_array_max_ulp', 'assert_warns', 'assert_no_warnings',
'assert_allclose', 'IgnoreException', 'clear_and_catch_warnings']
verbose = 0
def assert_(val, msg=''):
"""
Assert that works in release mode.
Accepts callable msg to allow deferring evaluation until failure.
The Python built-in ``assert`` does not work when executing code in
optimized mode (the ``-O`` flag) - no byte-code is generated for it.
For documentation on usage, refer to the Python documentation.
"""
if not val:
try:
smsg = msg()
except TypeError:
smsg = msg
raise AssertionError(smsg)
def gisnan(x):
"""like isnan, but always raise an error if type not supported instead of
returning a TypeError object.
Notes
-----
isnan and other ufunc sometimes return a NotImplementedType object instead
of raising any exception. This function is a wrapper to make sure an
exception is always raised.
This should be removed once this problem is solved at the Ufunc level."""
from numpy.core import isnan
st = isnan(x)
if isinstance(st, type(NotImplemented)):
raise TypeError("isnan not supported for this type")
return st
def gisfinite(x):
"""like isfinite, but always raise an error if type not supported instead of
returning a TypeError object.
Notes
-----
isfinite and other ufunc sometimes return a NotImplementedType object instead
of raising any exception. This function is a wrapper to make sure an
exception is always raised.
This should be removed once this problem is solved at the Ufunc level."""
from numpy.core import isfinite, errstate
with errstate(invalid='ignore'):
st = isfinite(x)
if isinstance(st, type(NotImplemented)):
raise TypeError("isfinite not supported for this type")
return st
def gisinf(x):
"""like isinf, but always raise an error if type not supported instead of
returning a TypeError object.
Notes
-----
isinf and other ufunc sometimes return a NotImplementedType object instead
of raising any exception. This function is a wrapper to make sure an
exception is always raised.
This should be removed once this problem is solved at the Ufunc level."""
from numpy.core import isinf, errstate
with errstate(invalid='ignore'):
st = isinf(x)
if isinstance(st, type(NotImplemented)):
raise TypeError("isinf not supported for this type")
return st
def rand(*args):
"""Returns an array of random numbers with the given shape.
This only uses the standard library, so it is useful for testing purposes.
"""
import random
from numpy.core import zeros, float64
results = zeros(args, float64)
f = results.flat
for i in range(len(f)):
f[i] = random.random()
return results
if os.name == 'nt':
# Code "stolen" from enthought/debug/memusage.py
def GetPerformanceAttributes(object, counter, instance=None,
inum=-1, format=None, machine=None):
# NOTE: Many counters require 2 samples to give accurate results,
# including "% Processor Time" (as by definition, at any instant, a
# thread's CPU usage is either 0 or 100). To read counters like this,
# you should copy this function, but keep the counter open, and call
# CollectQueryData() each time you need to know.
# See http://msdn.microsoft.com/library/en-us/dnperfmo/html/perfmonpt2.asp
# My older explanation for this was that the "AddCounter" process forced
# the CPU to 100%, but the above makes more sense :)
import win32pdh
if format is None:
format = win32pdh.PDH_FMT_LONG
path = win32pdh.MakeCounterPath( (machine, object, instance, None, inum, counter))
hq = win32pdh.OpenQuery()
try:
hc = win32pdh.AddCounter(hq, path)
try:
win32pdh.CollectQueryData(hq)
type, val = win32pdh.GetFormattedCounterValue(hc, format)
return val
finally:
win32pdh.RemoveCounter(hc)
finally:
win32pdh.CloseQuery(hq)
def memusage(processName="python", instance=0):
# from win32pdhutil, part of the win32all package
import win32pdh
return GetPerformanceAttributes("Process", "Virtual Bytes",
processName, instance,
win32pdh.PDH_FMT_LONG, None)
elif sys.platform[:5] == 'linux':
def memusage(_proc_pid_stat='/proc/%s/stat' % (os.getpid())):
"""
Return virtual memory size in bytes of the running python.
"""
try:
f = open(_proc_pid_stat, 'r')
l = f.readline().split(' ')
f.close()
return int(l[22])
except:
return
else:
def memusage():
"""
Return memory usage of running python. [Not implemented]
"""
raise NotImplementedError
if sys.platform[:5] == 'linux':
def jiffies(_proc_pid_stat='/proc/%s/stat' % (os.getpid()),
_load_time=[]):
"""
Return number of jiffies elapsed.
Return number of jiffies (1/100ths of a second) that this
process has been scheduled in user mode. See man 5 proc.
"""
import time
if not _load_time:
_load_time.append(time.time())
try:
f = open(_proc_pid_stat, 'r')
l = f.readline().split(' ')
f.close()
return int(l[13])
except:
return int(100*(time.time()-_load_time[0]))
else:
# os.getpid is not in all platforms available.
# Using time is safe but inaccurate, especially when process
# was suspended or sleeping.
def jiffies(_load_time=[]):
"""
Return number of jiffies elapsed.
Return number of jiffies (1/100ths of a second) that this
process has been scheduled in user mode. See man 5 proc.
"""
import time
if not _load_time:
_load_time.append(time.time())
return int(100*(time.time()-_load_time[0]))
def build_err_msg(arrays, err_msg, header='Items are not equal:',
verbose=True, names=('ACTUAL', 'DESIRED'), precision=8):
msg = ['\n' + header]
if err_msg:
if err_msg.find('\n') == -1 and len(err_msg) < 79-len(header):
msg = [msg[0] + ' ' + err_msg]
else:
msg.append(err_msg)
if verbose:
for i, a in enumerate(arrays):
if isinstance(a, ndarray):
# precision argument is only needed if the objects are ndarrays
r_func = partial(array_repr, precision=precision)
else:
r_func = repr
try:
r = r_func(a)
except:
r = '[repr failed]'
if r.count('\n') > 3:
r = '\n'.join(r.splitlines()[:3])
r += '...'
msg.append(' %s: %s' % (names[i], r))
return '\n'.join(msg)
def assert_equal(actual,desired,err_msg='',verbose=True):
"""
Raises an AssertionError if two objects are not equal.
Given two objects (scalars, lists, tuples, dictionaries or numpy arrays),
check that all elements of these objects are equal. An exception is raised
at the first conflicting values.
Parameters
----------
actual : array_like
The object to check.
desired : array_like
The expected object.
err_msg : str, optional
The error message to be printed in case of failure.
verbose : bool, optional
If True, the conflicting values are appended to the error message.
Raises
------
AssertionError
If actual and desired are not equal.
Examples
--------
>>> np.testing.assert_equal([4,5], [4,6])
...
<type 'exceptions.AssertionError'>:
Items are not equal:
item=1
ACTUAL: 5
DESIRED: 6
"""
if isinstance(desired, dict):
if not isinstance(actual, dict):
raise AssertionError(repr(type(actual)))
assert_equal(len(actual), len(desired), err_msg, verbose)
for k, i in desired.items():
if k not in actual:
raise AssertionError(repr(k))
assert_equal(actual[k], desired[k], 'key=%r\n%s' % (k, err_msg), verbose)
return
if isinstance(desired, (list, tuple)) and isinstance(actual, (list, tuple)):
assert_equal(len(actual), len(desired), err_msg, verbose)
for k in range(len(desired)):
assert_equal(actual[k], desired[k], 'item=%r\n%s' % (k, err_msg), verbose)
return
from numpy.core import ndarray, isscalar, signbit
from numpy.lib import iscomplexobj, real, imag
if isinstance(actual, ndarray) or isinstance(desired, ndarray):
return assert_array_equal(actual, desired, err_msg, verbose)
msg = build_err_msg([actual, desired], err_msg, verbose=verbose)
# Handle complex numbers: separate into real/imag to handle
# nan/inf/negative zero correctly
# XXX: catch ValueError for subclasses of ndarray where iscomplex fail
try:
usecomplex = iscomplexobj(actual) or iscomplexobj(desired)
except ValueError:
usecomplex = False
if usecomplex:
if iscomplexobj(actual):
actualr = real(actual)
actuali = imag(actual)
else:
actualr = actual
actuali = 0
if iscomplexobj(desired):
desiredr = real(desired)
desiredi = imag(desired)
else:
desiredr = desired
desiredi = 0
try:
assert_equal(actualr, desiredr)
assert_equal(actuali, desiredi)
except AssertionError:
raise AssertionError(msg)
# Inf/nan/negative zero handling
try:
# isscalar test to check cases such as [np.nan] != np.nan
if isscalar(desired) != isscalar(actual):
raise AssertionError(msg)
# If one of desired/actual is not finite, handle it specially here:
# check that both are nan if any is a nan, and test for equality
# otherwise
if not (gisfinite(desired) and gisfinite(actual)):
isdesnan = gisnan(desired)
isactnan = gisnan(actual)
if isdesnan or isactnan:
if not (isdesnan and isactnan):
raise AssertionError(msg)
else:
if not desired == actual:
raise AssertionError(msg)
return
elif desired == 0 and actual == 0:
if not signbit(desired) == signbit(actual):
raise AssertionError(msg)
# If TypeError or ValueError raised while using isnan and co, just handle
# as before
except (TypeError, ValueError, NotImplementedError):
pass
# Explicitly use __eq__ for comparison, ticket #2552
if not (desired == actual):
raise AssertionError(msg)
def print_assert_equal(test_string, actual, desired):
"""
Test if two objects are equal, and print an error message if test fails.
The test is performed with ``actual == desired``.
Parameters
----------
test_string : str
The message supplied to AssertionError.
actual : object
The object to test for equality against `desired`.
desired : object
The expected result.
Examples
--------
>>> np.testing.print_assert_equal('Test XYZ of func xyz', [0, 1], [0, 1])
>>> np.testing.print_assert_equal('Test XYZ of func xyz', [0, 1], [0, 2])
Traceback (most recent call last):
...
AssertionError: Test XYZ of func xyz failed
ACTUAL:
[0, 1]
DESIRED:
[0, 2]
"""
import pprint
if not (actual == desired):
msg = StringIO()
msg.write(test_string)
msg.write(' failed\nACTUAL: \n')
pprint.pprint(actual, msg)
msg.write('DESIRED: \n')
pprint.pprint(desired, msg)
raise AssertionError(msg.getvalue())
def assert_almost_equal(actual,desired,decimal=7,err_msg='',verbose=True):
"""
Raises an AssertionError if two items are not equal up to desired
precision.
.. note:: It is recommended to use one of `assert_allclose`,
`assert_array_almost_equal_nulp` or `assert_array_max_ulp`
instead of this function for more consistent floating point
comparisons.
The test is equivalent to ``abs(desired-actual) < 0.5 * 10**(-decimal)``.
Given two objects (numbers or ndarrays), check that all elements of these
objects are almost equal. An exception is raised at conflicting values.
For ndarrays this delegates to assert_array_almost_equal
Parameters
----------
actual : array_like
The object to check.
desired : array_like
The expected object.
decimal : int, optional
Desired precision, default is 7.
err_msg : str, optional
The error message to be printed in case of failure.
verbose : bool, optional
If True, the conflicting values are appended to the error message.
Raises
------
AssertionError
If actual and desired are not equal up to specified precision.
See Also
--------
assert_allclose: Compare two array_like objects for equality with desired
relative and/or absolute precision.
assert_array_almost_equal_nulp, assert_array_max_ulp, assert_equal
Examples
--------
>>> import numpy.testing as npt
>>> npt.assert_almost_equal(2.3333333333333, 2.33333334)
>>> npt.assert_almost_equal(2.3333333333333, 2.33333334, decimal=10)
...
<type 'exceptions.AssertionError'>:
Items are not equal:
ACTUAL: 2.3333333333333002
DESIRED: 2.3333333399999998
>>> npt.assert_almost_equal(np.array([1.0,2.3333333333333]),
... np.array([1.0,2.33333334]), decimal=9)
...
<type 'exceptions.AssertionError'>:
Arrays are not almost equal
<BLANKLINE>
(mismatch 50.0%)
x: array([ 1. , 2.33333333])
y: array([ 1. , 2.33333334])
"""
from numpy.core import ndarray
from numpy.lib import iscomplexobj, real, imag
# Handle complex numbers: separate into real/imag to handle
# nan/inf/negative zero correctly
# XXX: catch ValueError for subclasses of ndarray where iscomplex fail
try:
usecomplex = iscomplexobj(actual) or iscomplexobj(desired)
except ValueError:
usecomplex = False
def _build_err_msg():
header = ('Arrays are not almost equal to %d decimals' % decimal)
return build_err_msg([actual, desired], err_msg, verbose=verbose,
header=header)
if usecomplex:
if iscomplexobj(actual):
actualr = real(actual)
actuali = imag(actual)
else:
actualr = actual
actuali = 0
if iscomplexobj(desired):
desiredr = real(desired)
desiredi = imag(desired)
else:
desiredr = desired
desiredi = 0
try:
assert_almost_equal(actualr, desiredr, decimal=decimal)
assert_almost_equal(actuali, desiredi, decimal=decimal)
except AssertionError:
raise AssertionError(_build_err_msg())
if isinstance(actual, (ndarray, tuple, list)) \
or isinstance(desired, (ndarray, tuple, list)):
return assert_array_almost_equal(actual, desired, decimal, err_msg)
try:
# If one of desired/actual is not finite, handle it specially here:
# check that both are nan if any is a nan, and test for equality
# otherwise
if not (gisfinite(desired) and gisfinite(actual)):
if gisnan(desired) or gisnan(actual):
if not (gisnan(desired) and gisnan(actual)):
raise AssertionError(_build_err_msg())
else:
if not desired == actual:
raise AssertionError(_build_err_msg())
return
except (NotImplementedError, TypeError):
pass
if round(abs(desired - actual), decimal) != 0:
raise AssertionError(_build_err_msg())
def assert_approx_equal(actual,desired,significant=7,err_msg='',verbose=True):
"""
Raises an AssertionError if two items are not equal up to significant
digits.
.. note:: It is recommended to use one of `assert_allclose`,
`assert_array_almost_equal_nulp` or `assert_array_max_ulp`
instead of this function for more consistent floating point
comparisons.
Given two numbers, check that they are approximately equal.
Approximately equal is defined as the number of significant digits
that agree.
Parameters
----------
actual : scalar
The object to check.
desired : scalar
The expected object.
significant : int, optional
Desired precision, default is 7.
err_msg : str, optional
The error message to be printed in case of failure.
verbose : bool, optional
If True, the conflicting values are appended to the error message.
Raises
------
AssertionError
If actual and desired are not equal up to specified precision.
See Also
--------
assert_allclose: Compare two array_like objects for equality with desired
relative and/or absolute precision.
assert_array_almost_equal_nulp, assert_array_max_ulp, assert_equal
Examples
--------
>>> np.testing.assert_approx_equal(0.12345677777777e-20, 0.1234567e-20)
>>> np.testing.assert_approx_equal(0.12345670e-20, 0.12345671e-20,
significant=8)
>>> np.testing.assert_approx_equal(0.12345670e-20, 0.12345672e-20,
significant=8)
...
<type 'exceptions.AssertionError'>:
Items are not equal to 8 significant digits:
ACTUAL: 1.234567e-021
DESIRED: 1.2345672000000001e-021
the evaluated condition that raises the exception is
>>> abs(0.12345670e-20/1e-21 - 0.12345672e-20/1e-21) >= 10**-(8-1)
True
"""
import numpy as np
(actual, desired) = map(float, (actual, desired))
if desired == actual:
return
# Normalized the numbers to be in range (-10.0,10.0)
# scale = float(pow(10,math.floor(math.log10(0.5*(abs(desired)+abs(actual))))))
with np.errstate(invalid='ignore'):
scale = 0.5*(np.abs(desired) + np.abs(actual))
scale = np.power(10, np.floor(np.log10(scale)))
try:
sc_desired = desired/scale
except ZeroDivisionError:
sc_desired = 0.0
try:
sc_actual = actual/scale
except ZeroDivisionError:
sc_actual = 0.0
msg = build_err_msg([actual, desired], err_msg,
header='Items are not equal to %d significant digits:' %
significant,
verbose=verbose)
try:
# If one of desired/actual is not finite, handle it specially here:
# check that both are nan if any is a nan, and test for equality
# otherwise
if not (gisfinite(desired) and gisfinite(actual)):
if gisnan(desired) or gisnan(actual):
if not (gisnan(desired) and gisnan(actual)):
raise AssertionError(msg)
else:
if not desired == actual:
raise AssertionError(msg)
return
except (TypeError, NotImplementedError):
pass
if np.abs(sc_desired - sc_actual) >= np.power(10., -(significant-1)):
raise AssertionError(msg)
def assert_array_compare(comparison, x, y, err_msg='', verbose=True,
header='', precision=6):
from numpy.core import array, isnan, isinf, any, all, inf
x = array(x, copy=False, subok=True)
y = array(y, copy=False, subok=True)
def safe_comparison(*args, **kwargs):
# There are a number of cases where comparing two arrays hits special
# cases in array_richcompare, specifically around strings and void
# dtypes. Basically, we just can't do comparisons involving these
# types, unless both arrays have exactly the *same* type. So
# e.g. you can apply == to two string arrays, or two arrays with
# identical structured dtypes. But if you compare a non-string array
# to a string array, or two arrays with non-identical structured
# dtypes, or anything like that, then internally stuff blows up.
# Currently, when things blow up, we just return a scalar False or
# True. But we also emit a DeprecationWarning, b/c eventually we
# should raise an error here. (Ideally we might even make this work
# properly, but since that will require rewriting a bunch of how
# ufuncs work then we are not counting on that.)
#
# The point of this little function is to let the DeprecationWarning
# pass (or maybe eventually catch the errors and return False, I
# dunno, that's a little trickier and we can figure that out when the
# time comes).
with warnings.catch_warnings():
warnings.filterwarnings("ignore", category=DeprecationWarning)
return comparison(*args, **kwargs)
def isnumber(x):
return x.dtype.char in '?bhilqpBHILQPefdgFDG'
def chk_same_position(x_id, y_id, hasval='nan'):
"""Handling nan/inf: check that x and y have the nan/inf at the same
locations."""
try:
assert_array_equal(x_id, y_id)
except AssertionError:
msg = build_err_msg([x, y],
err_msg + '\nx and y %s location mismatch:'
% (hasval), verbose=verbose, header=header,
names=('x', 'y'), precision=precision)
raise AssertionError(msg)
try:
cond = (x.shape == () or y.shape == ()) or x.shape == y.shape
if not cond:
msg = build_err_msg([x, y],
err_msg
+ '\n(shapes %s, %s mismatch)' % (x.shape,
y.shape),
verbose=verbose, header=header,
names=('x', 'y'), precision=precision)
if not cond:
raise AssertionError(msg)
if isnumber(x) and isnumber(y):
x_isnan, y_isnan = isnan(x), isnan(y)
x_isinf, y_isinf = isinf(x), isinf(y)
# Validate that the special values are in the same place
if any(x_isnan) or any(y_isnan):
chk_same_position(x_isnan, y_isnan, hasval='nan')
if any(x_isinf) or any(y_isinf):
# Check +inf and -inf separately, since they are different
chk_same_position(x == +inf, y == +inf, hasval='+inf')
chk_same_position(x == -inf, y == -inf, hasval='-inf')
# Combine all the special values
x_id, y_id = x_isnan, y_isnan
x_id |= x_isinf
y_id |= y_isinf
# Only do the comparison if actual values are left
if all(x_id):
return
if any(x_id):
val = safe_comparison(x[~x_id], y[~y_id])
else:
val = safe_comparison(x, y)
else:
val = safe_comparison(x, y)
if isinstance(val, bool):
cond = val
reduced = [0]
else:
reduced = val.ravel()
cond = reduced.all()
reduced = reduced.tolist()
if not cond:
match = 100-100.0*reduced.count(1)/len(reduced)
msg = build_err_msg([x, y],
err_msg
+ '\n(mismatch %s%%)' % (match,),
verbose=verbose, header=header,
names=('x', 'y'), precision=precision)
if not cond:
raise AssertionError(msg)
except ValueError:
import traceback
efmt = traceback.format_exc()
header = 'error during assertion:\n\n%s\n\n%s' % (efmt, header)
msg = build_err_msg([x, y], err_msg, verbose=verbose, header=header,
names=('x', 'y'), precision=precision)
raise ValueError(msg)
def assert_array_equal(x, y, err_msg='', verbose=True):
"""
Raises an AssertionError if two array_like objects are not equal.
Given two array_like objects, check that the shape is equal and all
elements of these objects are equal. An exception is raised at
shape mismatch or conflicting values. In contrast to the standard usage
in numpy, NaNs are compared like numbers, no assertion is raised if
both objects have NaNs in the same positions.
The usual caution for verifying equality with floating point numbers is
advised.
Parameters
----------
x : array_like
The actual object to check.
y : array_like
The desired, expected object.
err_msg : str, optional
The error message to be printed in case of failure.
verbose : bool, optional
If True, the conflicting values are appended to the error message.
Raises
------
AssertionError
If actual and desired objects are not equal.
See Also
--------
assert_allclose: Compare two array_like objects for equality with desired
relative and/or absolute precision.
assert_array_almost_equal_nulp, assert_array_max_ulp, assert_equal
Examples
--------
The first assert does not raise an exception:
>>> np.testing.assert_array_equal([1.0,2.33333,np.nan],
... [np.exp(0),2.33333, np.nan])
Assert fails with numerical inprecision with floats:
>>> np.testing.assert_array_equal([1.0,np.pi,np.nan],
... [1, np.sqrt(np.pi)**2, np.nan])
...
<type 'exceptions.ValueError'>:
AssertionError:
Arrays are not equal
<BLANKLINE>
(mismatch 50.0%)
x: array([ 1. , 3.14159265, NaN])
y: array([ 1. , 3.14159265, NaN])
Use `assert_allclose` or one of the nulp (number of floating point values)
functions for these cases instead:
>>> np.testing.assert_allclose([1.0,np.pi,np.nan],
... [1, np.sqrt(np.pi)**2, np.nan],
... rtol=1e-10, atol=0)
"""
assert_array_compare(operator.__eq__, x, y, err_msg=err_msg,
verbose=verbose, header='Arrays are not equal')
def assert_array_almost_equal(x, y, decimal=6, err_msg='', verbose=True):
"""
Raises an AssertionError if two objects are not equal up to desired
precision.
.. note:: It is recommended to use one of `assert_allclose`,
`assert_array_almost_equal_nulp` or `assert_array_max_ulp`
instead of this function for more consistent floating point
comparisons.
The test verifies identical shapes and verifies values with
``abs(desired-actual) < 0.5 * 10**(-decimal)``.
Given two array_like objects, check that the shape is equal and all
elements of these objects are almost equal. An exception is raised at
shape mismatch or conflicting values. In contrast to the standard usage
in numpy, NaNs are compared like numbers, no assertion is raised if
both objects have NaNs in the same positions.
Parameters
----------
x : array_like
The actual object to check.
y : array_like
The desired, expected object.
decimal : int, optional
Desired precision, default is 6.
err_msg : str, optional
The error message to be printed in case of failure.
verbose : bool, optional
If True, the conflicting values are appended to the error message.
Raises
------
AssertionError
If actual and desired are not equal up to specified precision.
See Also
--------
assert_allclose: Compare two array_like objects for equality with desired
relative and/or absolute precision.
assert_array_almost_equal_nulp, assert_array_max_ulp, assert_equal
Examples
--------
the first assert does not raise an exception
>>> np.testing.assert_array_almost_equal([1.0,2.333,np.nan],
[1.0,2.333,np.nan])
>>> np.testing.assert_array_almost_equal([1.0,2.33333,np.nan],
... [1.0,2.33339,np.nan], decimal=5)
...
<type 'exceptions.AssertionError'>:
AssertionError:
Arrays are not almost equal
<BLANKLINE>
(mismatch 50.0%)
x: array([ 1. , 2.33333, NaN])
y: array([ 1. , 2.33339, NaN])
>>> np.testing.assert_array_almost_equal([1.0,2.33333,np.nan],
... [1.0,2.33333, 5], decimal=5)
<type 'exceptions.ValueError'>:
ValueError:
Arrays are not almost equal
x: array([ 1. , 2.33333, NaN])
y: array([ 1. , 2.33333, 5. ])
"""
from numpy.core import around, number, float_, result_type, array
from numpy.core.numerictypes import issubdtype
from numpy.core.fromnumeric import any as npany
def compare(x, y):
try:
if npany(gisinf(x)) or npany( gisinf(y)):
xinfid = gisinf(x)
yinfid = gisinf(y)
if not xinfid == yinfid:
return False
# if one item, x and y is +- inf
if x.size == y.size == 1:
return x == y
x = x[~xinfid]
y = y[~yinfid]
except (TypeError, NotImplementedError):
pass
# make sure y is an inexact type to avoid abs(MIN_INT); will cause
# casting of x later.
dtype = result_type(y, 1.)
y = array(y, dtype=dtype, copy=False, subok=True)
z = abs(x-y)
if not issubdtype(z.dtype, number):
z = z.astype(float_) # handle object arrays
return around(z, decimal) <= 10.0**(-decimal)
assert_array_compare(compare, x, y, err_msg=err_msg, verbose=verbose,
header=('Arrays are not almost equal to %d decimals' % decimal),
precision=decimal)
def assert_array_less(x, y, err_msg='', verbose=True):
"""
Raises an AssertionError if two array_like objects are not ordered by less
than.
Given two array_like objects, check that the shape is equal and all
elements of the first object are strictly smaller than those of the
second object. An exception is raised at shape mismatch or incorrectly
ordered values. Shape mismatch does not raise if an object has zero
dimension. In contrast to the standard usage in numpy, NaNs are
compared, no assertion is raised if both objects have NaNs in the same
positions.
Parameters
----------
x : array_like
The smaller object to check.
y : array_like
The larger object to compare.
err_msg : string
The error message to be printed in case of failure.
verbose : bool
If True, the conflicting values are appended to the error message.
Raises
------
AssertionError
If actual and desired objects are not equal.
See Also
--------
assert_array_equal: tests objects for equality
assert_array_almost_equal: test objects for equality up to precision
Examples
--------
>>> np.testing.assert_array_less([1.0, 1.0, np.nan], [1.1, 2.0, np.nan])
>>> np.testing.assert_array_less([1.0, 1.0, np.nan], [1, 2.0, np.nan])
...
<type 'exceptions.ValueError'>:
Arrays are not less-ordered
(mismatch 50.0%)
x: array([ 1., 1., NaN])
y: array([ 1., 2., NaN])
>>> np.testing.assert_array_less([1.0, 4.0], 3)
...
<type 'exceptions.ValueError'>:
Arrays are not less-ordered
(mismatch 50.0%)
x: array([ 1., 4.])
y: array(3)
>>> np.testing.assert_array_less([1.0, 2.0, 3.0], [4])
...
<type 'exceptions.ValueError'>:
Arrays are not less-ordered
(shapes (3,), (1,) mismatch)
x: array([ 1., 2., 3.])
y: array([4])
"""
assert_array_compare(operator.__lt__, x, y, err_msg=err_msg,
verbose=verbose,
header='Arrays are not less-ordered')
def runstring(astr, dict):
exec(astr, dict)
def assert_string_equal(actual, desired):
"""
Test if two strings are equal.
If the given strings are equal, `assert_string_equal` does nothing.
If they are not equal, an AssertionError is raised, and the diff
between the strings is shown.
Parameters
----------
actual : str
The string to test for equality against the expected string.
desired : str
The expected string.
Examples
--------
>>> np.testing.assert_string_equal('abc', 'abc')
>>> np.testing.assert_string_equal('abc', 'abcd')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
...
AssertionError: Differences in strings:
- abc+ abcd? +
"""
# delay import of difflib to reduce startup time
import difflib
if not isinstance(actual, str):
raise AssertionError(repr(type(actual)))
if not isinstance(desired, str):
raise AssertionError(repr(type(desired)))
if re.match(r'\A'+desired+r'\Z', actual, re.M):
return
diff = list(difflib.Differ().compare(actual.splitlines(1), desired.splitlines(1)))
diff_list = []
while diff:
d1 = diff.pop(0)
if d1.startswith(' '):
continue
if d1.startswith('- '):
l = [d1]
d2 = diff.pop(0)
if d2.startswith('? '):
l.append(d2)
d2 = diff.pop(0)
if not d2.startswith('+ '):
raise AssertionError(repr(d2))
l.append(d2)
d3 = diff.pop(0)
if d3.startswith('? '):
l.append(d3)
else:
diff.insert(0, d3)
if re.match(r'\A'+d2[2:]+r'\Z', d1[2:]):
continue
diff_list.extend(l)
continue
raise AssertionError(repr(d1))
if not diff_list:
return
msg = 'Differences in strings:\n%s' % (''.join(diff_list)).rstrip()
if actual != desired:
raise AssertionError(msg)
def rundocs(filename=None, raise_on_error=True):
"""
Run doctests found in the given file.
By default `rundocs` raises an AssertionError on failure.
Parameters
----------
filename : str
The path to the file for which the doctests are run.
raise_on_error : bool
Whether to raise an AssertionError when a doctest fails. Default is
True.
Notes
-----
The doctests can be run by the user/developer by adding the ``doctests``
argument to the ``test()`` call. For example, to run all tests (including
doctests) for `numpy.lib`:
>>> np.lib.test(doctests=True) #doctest: +SKIP
"""
import doctest
import imp
if filename is None:
f = sys._getframe(1)
filename = f.f_globals['__file__']
name = os.path.splitext(os.path.basename(filename))[0]
path = [os.path.dirname(filename)]
file, pathname, description = imp.find_module(name, path)
try:
m = imp.load_module(name, file, pathname, description)
finally:
file.close()
tests = doctest.DocTestFinder().find(m)
runner = doctest.DocTestRunner(verbose=False)
msg = []
if raise_on_error:
out = lambda s: msg.append(s)
else:
out = None
for test in tests:
runner.run(test, out=out)
if runner.failures > 0 and raise_on_error:
raise AssertionError("Some doctests failed:\n%s" % "\n".join(msg))
def raises(*args,**kwargs):
nose = import_nose()
return nose.tools.raises(*args,**kwargs)
def assert_raises(*args,**kwargs):
"""
assert_raises(exception_class, callable, *args, **kwargs)
Fail unless an exception of class exception_class is thrown
by callable when invoked with arguments args and keyword
arguments kwargs. If a different type of exception is
thrown, it will not be caught, and the test case will be
deemed to have suffered an error, exactly as for an
unexpected exception.
"""
nose = import_nose()
return nose.tools.assert_raises(*args,**kwargs)
assert_raises_regex_impl = None
def assert_raises_regex(exception_class, expected_regexp,
callable_obj=None, *args, **kwargs):
"""
Fail unless an exception of class exception_class and with message that
matches expected_regexp is thrown by callable when invoked with arguments
args and keyword arguments kwargs.
Name of this function adheres to Python 3.2+ reference, but should work in
all versions down to 2.6.
"""
nose = import_nose()
global assert_raises_regex_impl
if assert_raises_regex_impl is None:
try:
# Python 3.2+
assert_raises_regex_impl = nose.tools.assert_raises_regex
except AttributeError:
try:
# 2.7+
assert_raises_regex_impl = nose.tools.assert_raises_regexp
except AttributeError:
# 2.6
# This class is copied from Python2.7 stdlib almost verbatim
class _AssertRaisesContext(object):
"""A context manager used to implement TestCase.assertRaises* methods."""
def __init__(self, expected, expected_regexp=None):
self.expected = expected
self.expected_regexp = expected_regexp
def failureException(self, msg):
return AssertionError(msg)
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, tb):
if exc_type is None:
try:
exc_name = self.expected.__name__
except AttributeError:
exc_name = str(self.expected)
raise self.failureException(
"{0} not raised".format(exc_name))
if not issubclass(exc_type, self.expected):
# let unexpected exceptions pass through
return False
self.exception = exc_value # store for later retrieval
if self.expected_regexp is None:
return True
expected_regexp = self.expected_regexp
if isinstance(expected_regexp, basestring):
expected_regexp = re.compile(expected_regexp)
if not expected_regexp.search(str(exc_value)):
raise self.failureException(
'"%s" does not match "%s"' %
(expected_regexp.pattern, str(exc_value)))
return True
def impl(cls, regex, callable_obj, *a, **kw):
mgr = _AssertRaisesContext(cls, regex)
if callable_obj is None:
return mgr
with mgr:
callable_obj(*a, **kw)
assert_raises_regex_impl = impl
return assert_raises_regex_impl(exception_class, expected_regexp,
callable_obj, *args, **kwargs)
def decorate_methods(cls, decorator, testmatch=None):
"""
Apply a decorator to all methods in a class matching a regular expression.
The given decorator is applied to all public methods of `cls` that are
matched by the regular expression `testmatch`
(``testmatch.search(methodname)``). Methods that are private, i.e. start
with an underscore, are ignored.
Parameters
----------
cls : class
Class whose methods to decorate.
decorator : function
Decorator to apply to methods
testmatch : compiled regexp or str, optional
The regular expression. Default value is None, in which case the
nose default (``re.compile(r'(?:^|[\\b_\\.%s-])[Tt]est' % os.sep)``)
is used.
If `testmatch` is a string, it is compiled to a regular expression
first.
"""
if testmatch is None:
testmatch = re.compile(r'(?:^|[\\b_\\.%s-])[Tt]est' % os.sep)
else:
testmatch = re.compile(testmatch)
cls_attr = cls.__dict__
# delayed import to reduce startup time
from inspect import isfunction
methods = [_m for _m in cls_attr.values() if isfunction(_m)]
for function in methods:
try:
if hasattr(function, 'compat_func_name'):
funcname = function.compat_func_name
else:
funcname = function.__name__
except AttributeError:
# not a function
continue
if testmatch.search(funcname) and not funcname.startswith('_'):
setattr(cls, funcname, decorator(function))
return
def measure(code_str,times=1,label=None):
"""
Return elapsed time for executing code in the namespace of the caller.
The supplied code string is compiled with the Python builtin ``compile``.
The precision of the timing is 10 milli-seconds. If the code will execute
fast on this timescale, it can be executed many times to get reasonable
timing accuracy.
Parameters
----------
code_str : str
The code to be timed.
times : int, optional
The number of times the code is executed. Default is 1. The code is
only compiled once.
label : str, optional
A label to identify `code_str` with. This is passed into ``compile``
as the second argument (for run-time error messages).
Returns
-------
elapsed : float
Total elapsed time in seconds for executing `code_str` `times` times.
Examples
--------
>>> etime = np.testing.measure('for i in range(1000): np.sqrt(i**2)',
... times=times)
>>> print "Time for a single execution : ", etime / times, "s"
Time for a single execution : 0.005 s
"""
frame = sys._getframe(1)
locs, globs = frame.f_locals, frame.f_globals
code = compile(code_str,
'Test name: %s ' % label,
'exec')
i = 0
elapsed = jiffies()
while i < times:
i += 1
exec(code, globs, locs)
elapsed = jiffies() - elapsed
return 0.01*elapsed
def _assert_valid_refcount(op):
"""
Check that ufuncs don't mishandle refcount of object `1`.
Used in a few regression tests.
"""
import numpy as np
b = np.arange(100*100).reshape(100, 100)
c = b
i = 1
rc = sys.getrefcount(i)
for j in range(15):
d = op(b, c)
assert_(sys.getrefcount(i) >= rc)
del d # for pyflakes
def assert_allclose(actual, desired, rtol=1e-7, atol=0, equal_nan=False,
err_msg='', verbose=True):
"""
Raises an AssertionError if two objects are not equal up to desired
tolerance.
The test is equivalent to ``allclose(actual, desired, rtol, atol)``.
It compares the difference between `actual` and `desired` to
``atol + rtol * abs(desired)``.
.. versionadded:: 1.5.0
Parameters
----------
actual : array_like
Array obtained.
desired : array_like
Array desired.
rtol : float, optional
Relative tolerance.
atol : float, optional
Absolute tolerance.
equal_nan : bool, optional.
If True, NaNs will compare equal.
err_msg : str, optional
The error message to be printed in case of failure.
verbose : bool, optional
If True, the conflicting values are appended to the error message.
Raises
------
AssertionError
If actual and desired are not equal up to specified precision.
See Also
--------
assert_array_almost_equal_nulp, assert_array_max_ulp
Examples
--------
>>> x = [1e-5, 1e-3, 1e-1]
>>> y = np.arccos(np.cos(x))
>>> assert_allclose(x, y, rtol=1e-5, atol=0)
"""
import numpy as np
def compare(x, y):
return np.core.numeric.isclose(x, y, rtol=rtol, atol=atol,
equal_nan=equal_nan)
actual, desired = np.asanyarray(actual), np.asanyarray(desired)
header = 'Not equal to tolerance rtol=%g, atol=%g' % (rtol, atol)
assert_array_compare(compare, actual, desired, err_msg=str(err_msg),
verbose=verbose, header=header)
def assert_array_almost_equal_nulp(x, y, nulp=1):
"""
Compare two arrays relatively to their spacing.
This is a relatively robust method to compare two arrays whose amplitude
is variable.
Parameters
----------
x, y : array_like
Input arrays.
nulp : int, optional
The maximum number of unit in the last place for tolerance (see Notes).
Default is 1.
Returns
-------
None
Raises
------
AssertionError
If the spacing between `x` and `y` for one or more elements is larger
than `nulp`.
See Also
--------
assert_array_max_ulp : Check that all items of arrays differ in at most
N Units in the Last Place.
spacing : Return the distance between x and the nearest adjacent number.
Notes
-----
An assertion is raised if the following condition is not met::
abs(x - y) <= nulps * spacing(maximum(abs(x), abs(y)))
Examples
--------
>>> x = np.array([1., 1e-10, 1e-20])
>>> eps = np.finfo(x.dtype).eps
>>> np.testing.assert_array_almost_equal_nulp(x, x*eps/2 + x)
>>> np.testing.assert_array_almost_equal_nulp(x, x*eps + x)
Traceback (most recent call last):
...
AssertionError: X and Y are not equal to 1 ULP (max is 2)
"""
import numpy as np
ax = np.abs(x)
ay = np.abs(y)
ref = nulp * np.spacing(np.where(ax > ay, ax, ay))
if not np.all(np.abs(x-y) <= ref):
if np.iscomplexobj(x) or np.iscomplexobj(y):
msg = "X and Y are not equal to %d ULP" % nulp
else:
max_nulp = np.max(nulp_diff(x, y))
msg = "X and Y are not equal to %d ULP (max is %g)" % (nulp, max_nulp)
raise AssertionError(msg)
def assert_array_max_ulp(a, b, maxulp=1, dtype=None):
"""
Check that all items of arrays differ in at most N Units in the Last Place.
Parameters
----------
a, b : array_like
Input arrays to be compared.
maxulp : int, optional
The maximum number of units in the last place that elements of `a` and
`b` can differ. Default is 1.
dtype : dtype, optional
Data-type to convert `a` and `b` to if given. Default is None.
Returns
-------
ret : ndarray
Array containing number of representable floating point numbers between
items in `a` and `b`.
Raises
------
AssertionError
If one or more elements differ by more than `maxulp`.
See Also
--------
assert_array_almost_equal_nulp : Compare two arrays relatively to their
spacing.
Examples
--------
>>> a = np.linspace(0., 1., 100)
>>> res = np.testing.assert_array_max_ulp(a, np.arcsin(np.sin(a)))
"""
import numpy as np
ret = nulp_diff(a, b, dtype)
if not np.all(ret <= maxulp):
raise AssertionError("Arrays are not almost equal up to %g ULP" %
maxulp)
return ret
def nulp_diff(x, y, dtype=None):
"""For each item in x and y, return the number of representable floating
points between them.
Parameters
----------
x : array_like
first input array
y : array_like
second input array
dtype : dtype, optional
Data-type to convert `x` and `y` to if given. Default is None.
Returns
-------
nulp : array_like
number of representable floating point numbers between each item in x
and y.
Examples
--------
# By definition, epsilon is the smallest number such as 1 + eps != 1, so
# there should be exactly one ULP between 1 and 1 + eps
>>> nulp_diff(1, 1 + np.finfo(x.dtype).eps)
1.0
"""
import numpy as np
if dtype:
x = np.array(x, dtype=dtype)
y = np.array(y, dtype=dtype)
else:
x = np.array(x)
y = np.array(y)
t = np.common_type(x, y)
if np.iscomplexobj(x) or np.iscomplexobj(y):
raise NotImplementedError("_nulp not implemented for complex array")
x = np.array(x, dtype=t)
y = np.array(y, dtype=t)
if not x.shape == y.shape:
raise ValueError("x and y do not have the same shape: %s - %s" %
(x.shape, y.shape))
def _diff(rx, ry, vdt):
diff = np.array(rx-ry, dtype=vdt)
return np.abs(diff)
rx = integer_repr(x)
ry = integer_repr(y)
return _diff(rx, ry, t)
def _integer_repr(x, vdt, comp):
# Reinterpret binary representation of the float as sign-magnitude:
# take into account two-complement representation
# See also
# http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm
rx = x.view(vdt)
if not (rx.size == 1):
rx[rx < 0] = comp - rx[rx < 0]
else:
if rx < 0:
rx = comp - rx
return rx
def integer_repr(x):
"""Return the signed-magnitude interpretation of the binary representation of
x."""
import numpy as np
if x.dtype == np.float32:
return _integer_repr(x, np.int32, np.int32(-2**31))
elif x.dtype == np.float64:
return _integer_repr(x, np.int64, np.int64(-2**63))
else:
raise ValueError("Unsupported dtype %s" % x.dtype)
# The following two classes are copied from python 2.6 warnings module (context
# manager)
class WarningMessage(object):
"""
Holds the result of a single showwarning() call.
Deprecated in 1.8.0
Notes
-----
`WarningMessage` is copied from the Python 2.6 warnings module,
so it can be used in NumPy with older Python versions.
"""
_WARNING_DETAILS = ("message", "category", "filename", "lineno", "file",
"line")
def __init__(self, message, category, filename, lineno, file=None,
line=None):
local_values = locals()
for attr in self._WARNING_DETAILS:
setattr(self, attr, local_values[attr])
if category:
self._category_name = category.__name__
else:
self._category_name = None
def __str__(self):
return ("{message : %r, category : %r, filename : %r, lineno : %s, "
"line : %r}" % (self.message, self._category_name,
self.filename, self.lineno, self.line))
class WarningManager(object):
"""
A context manager that copies and restores the warnings filter upon
exiting the context.
The 'record' argument specifies whether warnings should be captured by a
custom implementation of ``warnings.showwarning()`` and be appended to a
list returned by the context manager. Otherwise None is returned by the
context manager. The objects appended to the list are arguments whose
attributes mirror the arguments to ``showwarning()``.
The 'module' argument is to specify an alternative module to the module
named 'warnings' and imported under that name. This argument is only useful
when testing the warnings module itself.
Deprecated in 1.8.0
Notes
-----
`WarningManager` is a copy of the ``catch_warnings`` context manager
from the Python 2.6 warnings module, with slight modifications.
It is copied so it can be used in NumPy with older Python versions.
"""
def __init__(self, record=False, module=None):
self._record = record
if module is None:
self._module = sys.modules['warnings']
else:
self._module = module
self._entered = False
def __enter__(self):
if self._entered:
raise RuntimeError("Cannot enter %r twice" % self)
self._entered = True
self._filters = self._module.filters
self._module.filters = self._filters[:]
self._showwarning = self._module.showwarning
if self._record:
log = []
def showwarning(*args, **kwargs):
log.append(WarningMessage(*args, **kwargs))
self._module.showwarning = showwarning
return log
else:
return None
def __exit__(self):
if not self._entered:
raise RuntimeError("Cannot exit %r without entering first" % self)
self._module.filters = self._filters
self._module.showwarning = self._showwarning
def assert_warns(warning_class, func, *args, **kw):
"""
Fail unless the given callable throws the specified warning.
A warning of class warning_class should be thrown by the callable when
invoked with arguments args and keyword arguments kwargs.
If a different type of warning is thrown, it will not be caught, and the
test case will be deemed to have suffered an error.
.. versionadded:: 1.4.0
Parameters
----------
warning_class : class
The class defining the warning that `func` is expected to throw.
func : callable
The callable to test.
\\*args : Arguments
Arguments passed to `func`.
\\*\\*kwargs : Kwargs
Keyword arguments passed to `func`.
Returns
-------
The value returned by `func`.
"""
with warnings.catch_warnings(record=True) as l:
warnings.simplefilter('always')
result = func(*args, **kw)
if not len(l) > 0:
raise AssertionError("No warning raised when calling %s"
% func.__name__)
if not l[0].category is warning_class:
raise AssertionError("First warning for %s is not a "
"%s( is %s)" % (func.__name__, warning_class, l[0]))
return result
def assert_no_warnings(func, *args, **kw):
"""
Fail if the given callable produces any warnings.
.. versionadded:: 1.7.0
Parameters
----------
func : callable
The callable to test.
\\*args : Arguments
Arguments passed to `func`.
\\*\\*kwargs : Kwargs
Keyword arguments passed to `func`.
Returns
-------
The value returned by `func`.
"""
with warnings.catch_warnings(record=True) as l:
warnings.simplefilter('always')
result = func(*args, **kw)
if len(l) > 0:
raise AssertionError("Got warnings when calling %s: %s"
% (func.__name__, l))
return result
def _gen_alignment_data(dtype=float32, type='binary', max_size=24):
"""
generator producing data with different alignment and offsets
to test simd vectorization
Parameters
----------
dtype : dtype
data type to produce
type : string
'unary': create data for unary operations, creates one input
and output array
'binary': create data for unary operations, creates two input
and output array
max_size : integer
maximum size of data to produce
Returns
-------
if type is 'unary' yields one output, one input array and a message
containing information on the data
if type is 'binary' yields one output array, two input array and a message
containing information on the data
"""
ufmt = 'unary offset=(%d, %d), size=%d, dtype=%r, %s'
bfmt = 'binary offset=(%d, %d, %d), size=%d, dtype=%r, %s'
for o in range(3):
for s in range(o + 2, max(o + 3, max_size)):
if type == 'unary':
inp = lambda: arange(s, dtype=dtype)[o:]
out = empty((s,), dtype=dtype)[o:]
yield out, inp(), ufmt % (o, o, s, dtype, 'out of place')
yield inp(), inp(), ufmt % (o, o, s, dtype, 'in place')
yield out[1:], inp()[:-1], ufmt % \
(o + 1, o, s - 1, dtype, 'out of place')
yield out[:-1], inp()[1:], ufmt % \
(o, o + 1, s - 1, dtype, 'out of place')
yield inp()[:-1], inp()[1:], ufmt % \
(o, o + 1, s - 1, dtype, 'aliased')
yield inp()[1:], inp()[:-1], ufmt % \
(o + 1, o, s - 1, dtype, 'aliased')
if type == 'binary':
inp1 = lambda: arange(s, dtype=dtype)[o:]
inp2 = lambda: arange(s, dtype=dtype)[o:]
out = empty((s,), dtype=dtype)[o:]
yield out, inp1(), inp2(), bfmt % \
(o, o, o, s, dtype, 'out of place')
yield inp1(), inp1(), inp2(), bfmt % \
(o, o, o, s, dtype, 'in place1')
yield inp2(), inp1(), inp2(), bfmt % \
(o, o, o, s, dtype, 'in place2')
yield out[1:], inp1()[:-1], inp2()[:-1], bfmt % \
(o + 1, o, o, s - 1, dtype, 'out of place')
yield out[:-1], inp1()[1:], inp2()[:-1], bfmt % \
(o, o + 1, o, s - 1, dtype, 'out of place')
yield out[:-1], inp1()[:-1], inp2()[1:], bfmt % \
(o, o, o + 1, s - 1, dtype, 'out of place')
yield inp1()[1:], inp1()[:-1], inp2()[:-1], bfmt % \
(o + 1, o, o, s - 1, dtype, 'aliased')
yield inp1()[:-1], inp1()[1:], inp2()[:-1], bfmt % \
(o, o + 1, o, s - 1, dtype, 'aliased')
yield inp1()[:-1], inp1()[:-1], inp2()[1:], bfmt % \
(o, o, o + 1, s - 1, dtype, 'aliased')
class IgnoreException(Exception):
"Ignoring this exception due to disabled feature"
@contextlib.contextmanager
def tempdir(*args, **kwargs):
"""Context manager to provide a temporary test folder.
All arguments are passed as this to the underlying tempfile.mkdtemp
function.
"""
tmpdir = mkdtemp(*args, **kwargs)
yield tmpdir
shutil.rmtree(tmpdir)
class clear_and_catch_warnings(warnings.catch_warnings):
""" Context manager that resets warning registry for catching warnings
Warnings can be slippery, because, whenever a warning is triggered, Python
adds a ``__warningregistry__`` member to the *calling* module. This makes
it impossible to retrigger the warning in this module, whatever you put in
the warnings filters. This context manager accepts a sequence of `modules`
as a keyword argument to its constructor and:
* stores and removes any ``__warningregistry__`` entries in given `modules`
on entry;
* resets ``__warningregistry__`` to its previous state on exit.
This makes it possible to trigger any warning afresh inside the context
manager without disturbing the state of warnings outside.
For compatibility with Python 3.0, please consider all arguments to be
keyword-only.
Parameters
----------
record : bool, optional
Specifies whether warnings should be captured by a custom
implementation of ``warnings.showwarning()`` and be appended to a list
returned by the context manager. Otherwise None is returned by the
context manager. The objects appended to the list are arguments whose
attributes mirror the arguments to ``showwarning()``.
modules : sequence, optional
Sequence of modules for which to reset warnings registry on entry and
restore on exit
Examples
--------
>>> import warnings
>>> with clear_and_catch_warnings(modules=[np.core.fromnumeric]):
... warnings.simplefilter('always')
... # do something that raises a warning in np.core.fromnumeric
"""
class_modules = ()
def __init__(self, record=False, modules=()):
self.modules = set(modules).union(self.class_modules)
self._warnreg_copies = {}
super(clear_and_catch_warnings, self).__init__(record=record)
def __enter__(self):
for mod in self.modules:
if hasattr(mod, '__warningregistry__'):
mod_reg = mod.__warningregistry__
self._warnreg_copies[mod] = mod_reg.copy()
mod_reg.clear()
return super(clear_and_catch_warnings, self).__enter__()
def __exit__(self, *exc_info):
super(clear_and_catch_warnings, self).__exit__(*exc_info)
for mod in self.modules:
if hasattr(mod, '__warningregistry__'):
mod.__warningregistry__.clear()
if mod in self._warnreg_copies:
mod.__warningregistry__.update(self._warnreg_copies[mod])