Functions are first-class objects in Python. This means that they can be passed around and used just like any other data type. For example, a function can be returned as a result:
def derivative(f): def compute(x): return (f(x+dx) - f(x))/dx return compute
In this example, the compute() function is returned as a result. Within this function, the variable dx is a free variable that will be bound when the function actually executes. The variable f was originally passed to the function derivative() and remains bound to that value in the function compute(). In addition, you can pass a function as an argument to another function:
# Find the zero of a function using Newton’s method # f is a function object representing a mathematical ...