Merge pull request #4451 from jtratner/better-assert-tests

TST: pandas/util/testing : test improvements and cleanups

Author: jreback

pandas/io/tests/test_pytables.py

@@ -1763,7 +1763,10 @@ def test_index_types(self):
 
         values = np.random.randn(2)
 
-        func = lambda l, r: tm.assert_series_equal(l, r, True, True, True)
+        func = lambda l, r: tm.assert_series_equal(l, r,
+                                                   check_dtype=True,
+                                                   check_index_type=True,
+                                                   check_series_type=True)
 
         with tm.assert_produces_warning(expected_warning=PerformanceWarning):
             ser = Series(values, [0, 'y'])

pandas/util/testing.py

@@ -1,8 +1,8 @@
 from __future__ import division
-
 # pylint: disable-msg=W0402
 
 import random
+import re
 import string
 import sys
 import tempfile
@@ -11,7 +11,7 @@
 import os
 
 from datetime import datetime
-from functools import wraps
+from functools import wraps, partial
 from contextlib import contextmanager
 from distutils.version import LooseVersion
 
@@ -130,27 +130,38 @@ def assert_isinstance(obj, class_type_or_tuple):
         "Expected object to be of type %r, found %r instead" % (
             type(obj), class_type_or_tuple))
 
-def assert_equal(actual, expected, msg=""):
-     assert expected == actual, "%s: %r != %r" % (msg, actual, expected)
+def assert_equal(a, b, msg=""):
+    """asserts that a equals b, like nose's assert_equal, but allows custom message to start.
+    Passes a and b to format string as well. So you can use '{0}' and '{1}' to display a and b.
+
+    Examples
+    --------
+    >>> assert_equal(2, 2, "apples")
+    >>> assert_equal(5.2, 1.2, "{0} was really a dead parrot")
+    Traceback (most recent call last):
+        ...
+    AssertionError: 5.2 was really a dead parrot: 5.2 != 1.2
+    """
+    assert a == b, "%s: %r != %r" % (msg.format(a,b), a, b)
+
 
 def assert_index_equal(left, right):
     if not left.equals(right):
         raise AssertionError("[index] left [{0} {1}], right [{2} {3}]".format(left.dtype,
                                                                               left,
                                                                               right,
                                                                               right.dtype))
+
+
 def assert_attr_equal(attr, left, right):
-    left_attr = getattr(left, attr, None)
-    right_attr = getattr(right, attr, None)
+    """checks attributes are equal. Both objects must have attribute."""
+    left_attr = getattr(left, attr)
+    right_attr = getattr(right, attr)
     assert_equal(left_attr,right_attr,"attr is not equal [{0}]" .format(attr))
 
 def isiterable(obj):
     return hasattr(obj, '__iter__')
 
-def assert_isinstance(obj, class_type_or_tuple):
-    """asserts that obj is an instance of class_type_or_tuple"""
-    assert isinstance(obj, class_type_or_tuple), (
-        "Expected object to be of type %r, found %r instead" % (type(obj), class_type_or_tuple))
 
 
 def assert_almost_equal(a, b, check_less_precise=False):
@@ -221,7 +232,6 @@ def assert_dict_equal(a, b, compare_keys=True):
 
 def assert_series_equal(left, right, check_dtype=True,
                         check_index_type=False,
-                        check_index_freq=False,
                         check_series_type=False,
                         check_less_precise=False):
     if check_series_type:
@@ -238,8 +248,6 @@ def assert_series_equal(left, right, check_dtype=True,
         assert_isinstance(left.index, type(right.index))
         assert_attr_equal('dtype', left.index, right.index)
         assert_attr_equal('inferred_type', left.index, right.index)
-    if check_index_freq:
-        assert_attr_equal('freqstr', left.index, right.index)
 
 
 def assert_frame_equal(left, right, check_dtype=True,
@@ -261,7 +269,7 @@ def assert_frame_equal(left, right, check_dtype=True,
         assert_index_equal(left.index, right.index)
 
     for i, col in enumerate(left.columns):
-        assert(col in right)
+        assert col in right
         lcol = left.icol(i)
         rcol = right.icol(i)
         assert_series_equal(lcol, rcol,
@@ -282,44 +290,36 @@ def assert_frame_equal(left, right, check_dtype=True,
         assert_attr_equal('names', left.columns, right.columns)
 
 
-def assert_panel_equal(left, right,
-                       check_panel_type=False,
-                       check_less_precise=False):
+def assert_panelnd_equal(left, right,
+                         check_panel_type=False,
+                         check_less_precise=False,
+                         assert_func=assert_frame_equal):
     if check_panel_type:
         assert_isinstance(left, type(right))
 
     for axis in ['items', 'major_axis', 'minor_axis']:
-        assert_index_equal(
-            getattr(left, axis, None), getattr(right, axis, None))
+        left_ind = getattr(left, axis)
+        right_ind = getattr(right, axis)
+        assert_index_equal(left_ind, right_ind)
 
     for col, series in compat.iteritems(left):
-        assert(col in right)
-        # TODO strangely check_names fails in py3 ?
-        assert_frame_equal(
-            series, right[col], check_less_precise=check_less_precise, check_names=False)
+        assert col in right, "non-matching column '%s'" % col
+        assert_func(series, right[col], check_less_precise=check_less_precise)
 
     for col in right:
-        assert(col in left)
-
-
-def assert_panel4d_equal(left, right,
-                         check_less_precise=False):
-    for axis in ['labels', 'items', 'major_axis', 'minor_axis']:
-        assert_index_equal(
-            getattr(left, axis, None), getattr(right, axis, None))
-
-    for col, series in compat.iteritems(left):
-        assert(col in right)
-        assert_panel_equal(
-            series, right[col], check_less_precise=check_less_precise)
+        assert col in left
 
-    for col in right:
-        assert(col in left)
+# TODO: strangely check_names fails in py3 ?
+_panel_frame_equal = partial(assert_frame_equal, check_names=False)
+assert_panel_equal = partial(assert_panelnd_equal,
+                             assert_func=_panel_frame_equal)
+assert_panel4d_equal = partial(assert_panelnd_equal,
+                               assert_func=assert_panel_equal)
 
 
 def assert_contains_all(iterable, dic):
     for k in iterable:
-        assert(k in dic)
+        assert k in dic, "Did not contain item: '%r'" % k
 
 
 def getCols(k):
@@ -986,7 +986,45 @@ def stdin_encoding(encoding=None):
     sys.stdin = _stdin
 
 
-def assertRaisesRegexp(exception, regexp, callable, *args, **kwargs):
+def assertRaises(_exception, _callable=None, *args, **kwargs):
+    """assertRaises that is usable as context manager or in a with statement
+
+    Exceptions that don't match the given Exception type fall through::
+
+    >>> with assertRaises(ValueError):
+    ...     raise TypeError("banana")
+    ...
+    Traceback (most recent call last):
+        ...
+    TypeError: banana
+
+    If it raises the given Exception type, the test passes
+    >>> with assertRaises(KeyError):
+    ...     dct = dict()
+    ...     dct["apple"]
+
+    If the expected error doesn't occur, it raises an error.
+    >>> with assertRaises(KeyError):
+    ...     dct = {'apple':True}
+    ...     dct["apple"]
+    Traceback (most recent call last):
+        ...
+    AssertionError: KeyError not raised.
+
+    In addition to using it as a contextmanager, you can also use it as a
+    function, just like the normal assertRaises
+
+    >>> assertRaises(TypeError, ",".join, [1, 3, 5]);
+    """
+    manager = _AssertRaisesContextmanager(exception=_exception)
+    # don't return anything if usedin function form
+    if _callable is not None:
+        with manager:
+            _callable(*args, **kwargs)
+    else:
+        return manager
+
+def assertRaisesRegexp(_exception, _regexp, _callable=None, *args, **kwargs):
     """ Port of assertRaisesRegexp from unittest in Python 2.7 - used in with statement.
 
     Explanation from standard library:
@@ -997,46 +1035,71 @@ def assertRaisesRegexp(exception, regexp, callable, *args, **kwargs):
 
     You can pass either a regular expression or a compiled regular expression object.
     >>> assertRaisesRegexp(ValueError, 'invalid literal for.*XYZ',
-    ...                                int, 'XYZ')
+    ...                                int, 'XYZ');
     >>> import re
-    >>> assertRaisesRegexp(ValueError, re.compile('literal'), int, 'XYZ')
+    >>> assertRaisesRegexp(ValueError, re.compile('literal'), int, 'XYZ');
 
     If an exception of a different type is raised, it bubbles up.
 
-    >>> assertRaisesRegexp(TypeError, 'literal', int, 'XYZ')
+    >>> assertRaisesRegexp(TypeError, 'literal', int, 'XYZ');
     Traceback (most recent call last):
         ...
     ValueError: invalid literal for int() with base 10: 'XYZ'
-    >>> dct = {}
-    >>> assertRaisesRegexp(KeyError, 'pear', dct.__getitem__, 'apple')
+    >>> dct = dict()
+    >>> assertRaisesRegexp(KeyError, 'pear', dct.__getitem__, 'apple');
     Traceback (most recent call last):
         ...
     AssertionError: "pear" does not match "'apple'"
-    >>> assertRaisesRegexp(KeyError, 'apple', dct.__getitem__, 'apple')
-    >>> assertRaisesRegexp(Exception, 'operand type.*int.*dict', lambda : 2 + {})
-    """
-
-    import re
 
-    try:
-        callable(*args, **kwargs)
-    except Exception as e:
-        if not issubclass(e.__class__, exception):
-            # mimics behavior of unittest
-            raise
-        # don't recompile
-        if hasattr(regexp, "search"):
-            expected_regexp = regexp
-        else:
-            expected_regexp = re.compile(regexp)
-        if not expected_regexp.search(str(e)):
-            raise AssertionError('"%s" does not match "%s"' %
-                                 (expected_regexp.pattern, str(e)))
+    You can also use this in a with statement.
+    >>> with assertRaisesRegexp(TypeError, 'unsupported operand type\(s\)'):
+    ...     1 + {}
+    >>> with assertRaisesRegexp(TypeError, 'banana'):
+    ...     'apple'[0] = 'b'
+    Traceback (most recent call last):
+        ...
+    AssertionError: "banana" does not match "'str' object does not support \
+item assignment"
+    """
+    manager = _AssertRaisesContextmanager(exception=_exception, regexp=_regexp)
+    if _callable is not None:
+        with manager:
+            _callable(*args, **kwargs)
     else:
-        # Apparently some exceptions don't have a __name__ attribute? Just
-        # aping unittest library here
-        name = getattr(exception, "__name__", str(exception))
-        raise AssertionError("{0} not raised".format(name))
+        return manager
+
+
+class _AssertRaisesContextmanager(object):
+    """handles the behind the scenes work for assertRaises and assertRaisesRegexp"""
+    def __init__(self, exception, regexp=None, *args, **kwargs):
+        self.exception = exception
+        if regexp is not None and not hasattr(regexp, "search"):
+            regexp = re.compile(regexp)
+        self.regexp = regexp
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        expected = self.exception
+        if not exc_type:
+            name = getattr(expected, "__name__", str(expected))
+            raise AssertionError("{0} not raised.".format(name))
+        if issubclass(exc_type, expected):
+            return self.handle_success(exc_type, exc_value, traceback)
+        return self.handle_failure(exc_type, exc_value, traceback)
+
+    def handle_failure(*args, **kwargs):
+        # Failed, so allow Exception to bubble up
+        return False
+
+    def handle_success(self, exc_type, exc_value, traceback):
+        if self.regexp is not None:
+            val = str(exc_value)
+            if not self.regexp.search(val):
+                raise AssertionError('"%s" does not match "%s"' %
+                                    (self.regexp.pattern, str(val)))
+        return True
 
 
 @contextmanager