Bitwise operations on .ix (Pandas)

dataframe, pandas, python-2.7

Solution

I think you're misunderstanding what's going on inside the square brackets-- `.ix` has nothing to do with it. If you parenthesize appropriately, this works:

>>> 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

Otherwise you're trying to perform a bitwise op on (presumably) a float. If it were an int, for example, then it'd "work":

>>> 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

Problem

Original source