Question

我有一个由

生成的pandas数据帧

dates = pandas.date_range('1/1/2000', periods=8)
df = pandas.DataFrame(rd.randn(8, 5), index=dates, columns=['call/put', 'expiration', 'strike', 'ask', 'bid'])
df.iloc[2,4]=0
df.iloc[2,3]=0
df.iloc[3,4]=0
df.iloc[3,3]=0
df.iloc[2,2]=0.5
df=df.append(df.iloc[2:3])
df.iloc[8:9,3:5]=1
df.iloc[8:9,2:3]=0.6
df=df.append(df.iloc[8:9])
df.iloc[9,2]=0.4

来自df我通过

获得df4

df4=df[(df["ask"]==0) & (df["bid"]==0)]

当通过df4行

进行循环时

for index, row in df4.iterrows():
  print index
  df_upperbound = df.iloc[index]

我得到索引KeyError：＆＃39;标签[2000-01-03 00:00:00]不在[index]＆＃39;中。在尝试时

for index, row in df4.iterrows():
  print index
  df_upperbound = df.xs[index]

我得到TypeError：＆＃39; instancemethod＆＃39;对象没有属性＆＃39; getitem ＆＃39;。我使用pandas 0.14.0和python 2.7.7。如何在df中迭代df4的索引？

Answer 1

documentation提供了多种方法来索引datetime索引DataFrame，例如：

In [64]:

index
Out[64]:
Timestamp('2000-01-03 00:00:00')
In [65]:

print df.ix[index.to_datetime()]
            call/put  expiration  strike  ask  bid
2000-01-03  0.830035    -0.42598     0.5    0    0
2000-01-03  0.830035    -0.42598     0.6    1    1
2000-01-03  0.830035    -0.42598     0.4    1    1
In [66]:

print df.ix[index]
            call/put  expiration  strike  ask  bid
2000-01-03  0.830035    -0.42598     0.5    0    0
2000-01-03  0.830035    -0.42598     0.6    1    1
2000-01-03  0.830035    -0.42598     0.4    1    1
In [67]:

print df[index.strftime('%m/%d/%y')]
            call/put  expiration  strike  ask  bid
2000-01-03  0.830035    -0.42598     0.5    0    0
2000-01-03  0.830035    -0.42598     0.6    1    1
2000-01-03  0.830035    -0.42598     0.4    1    1

datetime index KeyError：'标签[2000-01-03 00:00:00]不在[index]中

1 个答案: