Boolean Math

The Boolean Math node gives access to common boolean operations, such as AND, NOT, XOR, etc. Use it together with comparisons (which create Compare nodes) to build conditions.

@tree("Select Top")
def select_top(geometry: Geometry, threshold: float = 0.5):
    z = separate_xyz(vector=position().position).z
    above = z > threshold
    is_even = index().index % 2 == 0
    selection = boolean_math(boolean=above, boolean_2=is_even, operation="AND").boolean
    return delete_geometry(geometry=geometry, selection=selection).geometry

NOT only uses the first input:

boolean_math(boolean=above, operation="NOT").boolean

You cannot use the Python keywords and, or, and not on sockets. The script only builds the node tree, so it never sees the values that would decide the result. Use Boolean Math nodes instead.

If a condition gets long, a small helper function keeps it readable:

def all_of(*conditions):
    result = conditions[0]
    for condition in conditions[1:]:
        result = boolean_math(boolean=result, boolean_2=condition, operation="AND").boolean
    return result