Computer science: a note about method chaining

Self-tutoring about calling methods in object-oriented programming: the tutor mentions an error.

Sometimes one might mean to chain methods such as

new_ob=f1().f2().f3()

but get an error like “the function f2 has no attribute f3”. Such an error might happen because the parentheses on f2 have been forgotten:

new_ob=f1().f2.f3()

Without its parentheses, f2 hasn’t been called, so can’t return an object which contains the method f3. Likely, one wants, as above,

new_ob=f1().f2().f3()

Source:

stackoverflow.com

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.