Question

为什么会这样？

import pandas as pd
import numpy as np    
grid = pd.DataFrame(np.random.randn(10,3), columns=["X", "Y", "Z"])
year_velocities = pd.DataFrame()
hours = pd.date_range(start='1/1/2010', periods=10, freq='H')
temp_df = pd.DataFrame()
for h in hours:
    print h
    temp_df = grid.copy()
    temp_df["time"] = h.strftime("%Y-%m-%d %H:%M:%S")
    year_velocities = year_velocities.append(temp_df, ignore_index=True)

如果我更换

temp_df["time"] = h.strftime("%Y-%m-%d %H:%M:%S")

带

temp_df["time"] = h

它失败了？

我最终得到一个空的temp_df。

似乎我无法将TimeStamp分配给列？

更新：代码适用于这两种情况。当我尝试使用Anaconda Spyder Variable Explorer可视化temp_df和year_velocities的值时，会出现此问题。

>>> Traceback (most recent call last):
  File "C:\Users\aerg01341\AppData\Local\Continuum\Anaconda\lib\site-packages\spyderlib\widgets\dicteditor.py", line 411, in createEditor
    if not editor.setup_and_check(value):
  File "C:\Users\aerg01341\AppData\Local\Continuum\Anaconda\lib\site-packages\spyderlib\widgets\dataframeeditor.py", line 409, in setup_and_check
    self.dataModel = DataFrameModel(data, parent=self)
  File "C:\Users\aerg01341\AppData\Local\Continuum\Anaconda\lib\site-packages\spyderlib\widgets\dataframeeditor.py", line 75, in __init__
    self.max_min_col_update()
  File "C:\Users\aerg01341\AppData\Local\Continuum\Anaconda\lib\site-packages\spyderlib\widgets\dataframeeditor.py", line 90, in max_min_col_update
    df_abs = self.df[self.complex_intran].abs()
  File "C:\Users\aerg01341\AppData\Local\Continuum\Anaconda\lib\site-packages\pandas\core\generic.py", line 3662, in abs
    return np.abs(self)
TypeError: bad operand type for abs(): 'NaTType'

Pandas 0.14.1：为列分配时间戳失败

0 个答案: