filtering

When you say (a[‘x’]==1) and (a[‘y’]==10) You are implicitly asking Python to convert (a[‘x’]==1) and (a[‘y’]==10) to Boolean values. NumPy arrays (of length greater than 1) and Pandas objects such as Series do not have a Boolean value — in other words, they raise ValueError: The truth value of an array is ambiguous. Use a.empty, … Read more

The or and and python statements require truth-values. For pandas these are considered ambiguous so you should use “bitwise” | (or) or & (and) operations: df = df[(df[‘col’] < -0.25) | (df[‘col’] > 0.25)] These are overloaded for these kind of data structures to yield the element-wise or (or and). Just to add some more … Read more