numpy “TypeError: ufunc 'bitwise_and' not supported for the input types” when using a dynamically created boolean mask

Question

In numpy, if I have an array of floats, dynamically create a boolean mask of where this array equals a particular value and do a bitwise AND with a boolean array, I get an e

Answer 1

& has higher precedence than ==, so the expression

a == 2.0 & b

is the same as

a == (2.0 & b)

You get the error because bitwise and is not defined for a floating point scalar and a boolean array.

Add parentheses to get what you expected:

(a == 2.0) & b