Greater/less than comparisons between Pandas DataFrames/Series

Question

How can I perform comparisons between DataFrames and Series? I\'d like to mask elements in a DataFrame/Series that are greater/less than elements in another DataFrame/Series

Answer 1

The problem here is that it's interpreting the index as column values to perform the comparison, if you use .gt and pass axis=0 then you get the result you desire:

In [203]:
x.gt(x.mean(axis=1), axis=0)

Out[203]:
       a     b
0  False  True
1  False  True

You can see what I mean when you perform the comparison with the np array:

In [205]:
x > x.mean(axis=1).values

Out[205]:
       a      b
0  False  False
1  False   True

here you can see that the default axis for comparison is on the column, resulting in a different result