位運算上.IX（熊貓）

Question

爲什麼沒有開發商允許在.IX位操作？好奇這究竟是技術約束還是我忽略的邏輯問題。

df.ix[df["ptdelta"]<=0 & df["ptdelta"]>5] 

回溯是：

TypeError: ufunc 'bitwise_and' not supported for the input types, and the inputs could not be safely coerced to any supported types according to the casting rule 'safe' 

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Answer 1

我想你誤會這是怎麼回事廣場brackets-- .ix無關，用它做的內部。如果加上括號得當，這個工程：

>>> df = pd.DataFrame({"a": [-1,2,-3,4,6,-8.2]}) 
>>> df.ix[(df['a'] <= 0) | (df['a'] > 5)] 
    a 
0 -1.0 
2 -3.0 
4 6.0 
5 -8.2 

否則，你要嘗試執行的（大概）一個float按位運算。例如，如果它是一個整數，那麼它會「工作」：

>>> df['a'] <= 0 & df['a'] 
Traceback (most recent call last): 
    File "<ipython-input-40-9173361ec31b>", line 1, in <module> 
    df['a'] <= 0 & df['a'] 
TypeError: ufunc 'bitwise_and' not supported for the input types, and the inputs could not be safely coerced to any supported types according to the casting rule 'safe' 

>>> df['a'] <= 0 & df['a'].astype(int) 
0  True 
1 False 
2  True 
3 False 
4 False 
5  True 
Name: a, Dtype: bool