【发布时间】：2013-02-15 10:54:19
【问题描述】：
运行 pandas 文档中的代码示例时出现错误。
我怀疑这可能与我使用的 pandas 版本有关，但我无法确认。
pandas VERSION 0.10.1
numpy VERSION 1.7.0
scipy VERSION 0.12.0.dev-14b1e07
以下示例直接取自此处的 pandas 文档：
pandas - Time Deltas
这行得通
from datetime import datetime, timedelta
from pandas import *
s = Series(date_range('2012-1-1', periods=3, freq='D'))
s
Out[52]:
0 2012-01-01 00:00:00
1 2012-01-02 00:00:00
2 2012-01-03 00:00:00
这样
td = Series([ timedelta(days=i) for i in range(3) ])
td
Out[53]:
0 0:00:00
1 1 day, 0:00:00
2 2 days, 0:00:00
df = DataFrame(dict(A = s, B = td))
df
Out[54]:
A B
0 2012-01-01 00:00:00 0:00:00
1 2012-01-02 00:00:00 1 day, 0:00:00
2 2012-01-03 00:00:00 2 days, 0:00:00
这似乎与文档中的预期输出一致。
示例代码中的下一行产生错误：
df['C'] = df['A'] + df['B']
...
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-55-7057e174d79e> in <module>()
----> 1 df['C'] = df['A'] + df['B']
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/core/series.pyc in wrapper(self, other)
91 if self.index.equals(other.index):
92 name = _maybe_match_name(self, other)
---> 93 return Series(wrap_results(na_op(lvalues, rvalues)),
94 index=self.index, name=name)
95
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/core/series.pyc in na_op(x, y)
63 if isinstance(y, np.ndarray):
64 mask = notnull(x) & notnull(y)
---> 65 result[mask] = op(x[mask], y[mask])
66 else:
67 mask = notnull(x)
TypeError: ufunc add cannot use operands with types dtype('<M8[ns]') and dtype('O')
数据类型：
df.dtypes
Out[56]:
A datetime64[ns]
B object
同样，当我做加法/减法时，我得到一个错误：
s - s.max()
<ipython-input-57-8d53e24db927> in <module>()
----> 1 s - s.max()
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/core/series.pyc in wrapper(self, other)
78
79 if (com.is_datetime64_dtype(self) and
---> 80 com.is_datetime64_dtype(other)):
81 lvalues = lvalues.view('i8')
82 rvalues = rvalues.view('i8')
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/core/common.pyc in is_datetime64_dtype(arr_or_dtype)
1003 tipo = arr_or_dtype.type
1004 else:
-> 1005 tipo = arr_or_dtype.dtype.type
1006 return issubclass(tipo, np.datetime64)
1007
AttributeError: 'Timestamp' object has no attribute 'dtype'
此代码是一个要点，以便于参考。
https://gist.github.com/hernamesbarbara/5061972
感谢您的任何帮助或建议；非常感谢。
-奥斯汀
【问题讨论】：
标签： datetime pandas time-series series timedelta