我有一个 DataFrame，我想使用“str.contrains()”方法。当我阅读 pandas + dataframe - select by partial string 时，我相信我已经找到了如何做到这一点。但是，我不断收到值错误。
我的DataFrame如下:
ID,ENROLLMENT_DATE,TRAINER_MANAGING,TRAINER_OPERATOR,FIRST_VISIT_DATE
1536D,12-Feb-12,"06DA1B3-Lebanon NH",,15-Feb-12
F15D,18-May-12,"06405B2-Lebanon NH",,25-Jul-12
8096,8-Aug-12,"0643D38-Hanover NH","0643D38-Hanover NH",25-Jun-12
A036,1-Apr-12,"06CB8CF-Hanover NH","06CB8CF-Hanover NH",9-Aug-12
8944,19-Feb-12,"06D26AD-Hanover NH",,4-Feb-12
1004E,8-Jun-12,"06388B2-Lebanon NH",,24-Dec-11
11795,3-Jul-12,"0649597-White River VT","0649597-White River VT",30-Mar-12
30D7,11-Nov-12,"06D95A3-Hanover NH","06D95A3-Hanover NH",30-Nov-11
3AE2,21-Feb-12,"06405B2-Lebanon NH",,26-Oct-12
B0FE,17-Feb-12,"06D1B9D-Hartland VT",,16-Feb-12
127A1,11-Dec-11,"064456E-Hanover NH","064456E-Hanover NH",11-Nov-12
161FF,20-Feb-12,"0643D38-Hanover NH","0643D38-Hanover NH",3-Jul-12
A036,30-Nov-11,"063B208-Randolph VT","063B208-Randolph VT",
475B,25-Sep-12,"06D26AD-Hanover NH",,5-Nov-12
151A3,7-Mar-12,"06388B2-Lebanon NH",,16-Nov-12
CA62,3-Jan-12,,,
D31B,18-Dec-11,"06405B2-Lebanon NH",,9-Jan-12
20F5,8-Jul-12,"0669C50-Randolph VT",,3-Feb-12
8096,19-Dec-11,"0649597-White River VT","0649597-White River VT",9-Apr-12
14E48,1-Aug-12,"06D3206-Hanover NH",,
177F8,20-Aug-12,"063B208-Randolph VT","063B208-Randolph VT",5-May-12
553E,11-Oct-12,"06D95A3-Hanover NH","06D95A3-Hanover NH",8-Mar-12
12D5F,18-Jul-12,"0649597-White River VT","0649597-White River VT",2-Nov-12
C6DC,13-Apr-12,"06388B2-Lebanon NH",,
11795,27-Feb-12,"0643D38-Hanover NH","0643D38-Hanover NH",19-Jun-12
17B43,11-Aug-12,,,22-Oct-12
A036,11-Aug-12,"06D3206-Hanover NH",,19-Jun-12
然后我运行以下代码:
test = pandas.read_csv('testcsv.csv')
test[test.TRAINER_MANAGING.str.contains('Han', na=False)]
我收到以下错误:
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-54-e0c4624c9346> in <module>()
----> 1 test[test.TRAINER_MANAGING.str.contains('Han', na=False)]
.virtualenvs/ipython/lib/python2.7/site-packages/pandas/core/frame.pyc in __getitem__(self, key)
1958
1959 # also raises Exception if object array with NA values
-> 1960 if com._is_bool_indexer(key):
1961 key = np.asarray(key, dtype=bool)
1962 return self._getitem_array(key)
.virtualenvs/ipython/lib/python2.7/site-packages/pandas/core/common.pyc in _is_bool_indexer(key)
685 if not lib.is_bool_array(key):
686 if isnull(key).any():
--> 687 raise ValueError('cannot index with vector containing '
688 'NA / NaN values')
689 return False
ValueError: cannot index with vector containing NA / NaN values
我觉得我缺少一些简单的东西。任何帮助，将不胜感激。
最佳答案
您的字符串搜索仍然返回 nan 值，而切片操作仅适用于 bool 值。看起来“na=False”不起作用(在这种情况下？)，我可以使用最新(已发布)的 Pandas 版本在我的机器上复制它。
您可以通过首先对结果应用 .fillna() 函数来解决它，例如:
test[test.TRAINER_MANAGING.str.contains('Han').fillna(False)]
哪个返回:
ID ENROLLMENT_DATE TRAINER_MANAGING TRAINER_OPERATOR FIRST_VISIT_DATE
2 8096 8-Aug-12 0643D38-Hanover NH 0643D38-Hanover NH 25-Jun-12
3 A036 1-Apr-12 06CB8CF-Hanover NH 06CB8CF-Hanover NH 9-Aug-12
4 8944 19-Feb-12 06D26AD-Hanover NH NaN 4-Feb-12
7 30D7 11-Nov-12 06D95A3-Hanover NH 06D95A3-Hanover NH 30-Nov-11
10 127A1 11-Dec-11 064456E-Hanover NH 064456E-Hanover NH 11-Nov-12
11 161FF 20-Feb-12 0643D38-Hanover NH 0643D38-Hanover NH 3-Jul-12
13 475B 25-Sep-12 06D26AD-Hanover NH NaN 5-Nov-12
19 14E48 1-Aug-12 06D3206-Hanover NH NaN NaN
21 553E 11-Oct-12 06D95A3-Hanover NH 06D95A3-Hanover NH 8-Mar-12
24 11795 27-Feb-12 0643D38-Hanover NH 0643D38-Hanover NH 19-Jun-12
26 A036 11-Aug-12 06D3206-Hanover NH NaN 19-Jun-12
我以前从未使用过 str.contains 函数，所以我不确定它是否不能正常工作。如果它应该像您的示例一样工作，我们应该在 github 上提出一个问题。
关于python - 在 Pandas 中切片时出现值错误，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14731714/