Is it possible to nest functions inside of functions? If so, what purposes does it have? I have some example code below to show what I mean.
def theFunction():
print "This is a function"
def functionception():
print "Bad inception joke...."
Once again, is this possible? If so, what purposes does it serve, and how is it used?
Yes you can.
You can have the outer function do some boundary condition checks on variables passed to the outer function and pass the "valid/sanitized" variables to the inner function to do the actual processing/manipulation. This is in fact how decorators work.
This blog explains in detail how outer function inner function combination works in decorators - http://simeonfranklin.com/blog/2012/jul/1/python-decorators-in-12-steps/
Yes it's possible, and is frequently used when decorating other functions, for example
def memo(f):
cache = {}
def func(*args):
if args not in cache:
cache[args] = f(*args)
return cache[args]
return func
Example usage:
@memo
def memoized_func(some_arg):
return some_arg ** 2
Here the inner function func is used to wrap the argument function f, providing additional functionality (in this case saving the results of previous computations).
