<p dir="auto">I got the following two errors running "nosetests pandas":</p>
<h2 dir="auto">FAIL: test_fred_multi (pandas.io.tests.test_data.TestFred)</h2>
<p dir="auto">Traceback (most recent call last):<br>
File "/Users/hbi16088/python-virtual-env/basic/lib/python2.7/site-packages/pandas/util/testing.py", line 1135, in wrapper<br>
return t(_args, *_kwargs)<br>
File "/Users/hbi16088/python-virtual-env/basic/lib/python2.7/site-packages/pandas/io/tests/test_data.py", line 455, in test_fred_multi<br>
assert_frame_equal(received, expected, check_less_precise=True)<br>
File "/Users/hbi16088/python-virtual-env/basic/lib/python2.7/site-packages/pandas/util/testing.py", line 509, in assert_frame_equal<br>
check_less_precise=check_less_precise)<br>
File "/Users/hbi16088/python-virtual-env/basic/lib/python2.7/site-packages/pandas/util/testing.py", line 458, in assert_series_equal<br>
assert_almost_equal(left.values, right.values, check_less_precise)<br>
File "testing.pyx", line 58, in pandas._testing.assert_almost_equal (pandas/src/testing.c:2464)<br>
File "testing.pyx", line 93, in pandas._testing.assert_almost_equal (pandas/src/testing.c:1716)<br>
File "testing.pyx", line 140, in pandas._testing.assert_almost_equal (pandas/src/testing.c:2300)<br>
AssertionError: expected 217.47800 but got 217.46600</p>
<h1 dir="auto"></h1>
<h2 dir="auto">FAIL: test_fred_parts (pandas.io.tests.test_data.TestFred)</h2>
<p dir="auto">Traceback (most recent call last):<br>
File "/Users/hbi16088/python-virtual-env/basic/lib/python2.7/site-packages/pandas/util/testing.py", line 1135, in wrapper<br>
return t(_args, *_kwargs)<br>
File "/Users/hbi16088/python-virtual-env/basic/lib/python2.7/site-packages/pandas/io/tests/test_data.py", line 424, in test_fred_parts<br>
self.assertEqual(df.ix['2010-05-01'][0], 217.23)<br>
AssertionError: 217.29900000000001 != 217.23</p>
<p dir="auto">Note the duplication of the assignment is not a copy/paste error-- the first one works, the second one fails, presumably because a different path is taken if the column already exists than if it doesn't.</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&gt;&gt;&gt; pd.__version__
'0.12.0-1081-ge684bdc'
&gt;&gt;&gt; df = pd.DataFrame({&quot;A&quot;: [1,2]})
&gt;&gt;&gt; df._is_copy
False
&gt;&gt;&gt; df.to_pickle(&quot;tmp.pk&quot;)
&gt;&gt;&gt; df2 = pd.read_pickle(&quot;tmp.pk&quot;)
&gt;&gt;&gt; hasattr(df2, &quot;_is_copy&quot;)
False
&gt;&gt;&gt; df2[&quot;B&quot;] = df2[&quot;A&quot;]
&gt;&gt;&gt; df2[&quot;B&quot;] = df2[&quot;A&quot;]
Traceback (most recent call last):
  File &quot;&lt;ipython-input-155-e1fb2db534a8&gt;&quot;, line 1, in &lt;module&gt;
    df2[&quot;B&quot;] = df2[&quot;A&quot;]
  File &quot;/usr/local/lib/python2.7/dist-packages/pandas-0.12.0_1081_ge684bdc-py2.7-linux-i686.egg/pandas/core/frame.py&quot;, line 1841, in __setitem__
    self._set_item(key, value)
  File &quot;/usr/local/lib/python2.7/dist-packages/pandas-0.12.0_1081_ge684bdc-py2.7-linux-i686.egg/pandas/core/frame.py&quot;, line 1907, in _set_item
    self._check_setitem_copy()
  File &quot;/usr/local/lib/python2.7/dist-packages/pandas-0.12.0_1081_ge684bdc-py2.7-linux-i686.egg/pandas/core/generic.py&quot;, line 1001, in _check_setitem_copy
    if self._is_copy:
  File &quot;/usr/local/lib/python2.7/dist-packages/pandas-0.12.0_1081_ge684bdc-py2.7-linux-i686.egg/pandas/core/generic.py&quot;, line 1525, in __getattr__
    (type(self).__name__, name))
AttributeError: 'DataFrame' object has no attribute '_is_copy'"><pre class="notranslate"><code class="notranslate">&gt;&gt;&gt; pd.__version__
'0.12.0-1081-ge684bdc'
&gt;&gt;&gt; df = pd.DataFrame({"A": [1,2]})
&gt;&gt;&gt; df._is_copy
False
&gt;&gt;&gt; df.to_pickle("tmp.pk")
&gt;&gt;&gt; df2 = pd.read_pickle("tmp.pk")
&gt;&gt;&gt; hasattr(df2, "_is_copy")
False
&gt;&gt;&gt; df2["B"] = df2["A"]
&gt;&gt;&gt; df2["B"] = df2["A"]
Traceback (most recent call last):
  File "&lt;ipython-input-155-e1fb2db534a8&gt;", line 1, in &lt;module&gt;
    df2["B"] = df2["A"]
  File "/usr/local/lib/python2.7/dist-packages/pandas-0.12.0_1081_ge684bdc-py2.7-linux-i686.egg/pandas/core/frame.py", line 1841, in __setitem__
    self._set_item(key, value)
  File "/usr/local/lib/python2.7/dist-packages/pandas-0.12.0_1081_ge684bdc-py2.7-linux-i686.egg/pandas/core/frame.py", line 1907, in _set_item
    self._check_setitem_copy()
  File "/usr/local/lib/python2.7/dist-packages/pandas-0.12.0_1081_ge684bdc-py2.7-linux-i686.egg/pandas/core/generic.py", line 1001, in _check_setitem_copy
    if self._is_copy:
  File "/usr/local/lib/python2.7/dist-packages/pandas-0.12.0_1081_ge684bdc-py2.7-linux-i686.egg/pandas/core/generic.py", line 1525, in __getattr__
    (type(self).__name__, name))
AttributeError: 'DataFrame' object has no attribute '_is_copy'
</code></pre></div>