A simple self-modifying function in Python¶
Replacing its own definition is a fun/horrifying thing that a Python function can do:
def bla():
def new_bla():
print('new bla')
global bla
bla = new_bla
print('bla')
bla() # prints "bla"
bla() # prints "new bla"
I don’t have any use for this trick, but mayyyyyybe you can use that for lazy initialization
of something, and then not wasting (a tiny bit of) time on the if check in subsequent
function calls? E.g., replacing
global_resource = None
def do_something_with_lazy_initialization():
if global_resource is None:
global_resource = initialize_the_resource()
print('about to do stuff')
do_stuff_with(global_resource)
with
def do_something_with_lazy_initialization():
def actually_doing_something():
print('about to do stuff')
do_stuff_with(global_resource)
global_resource = initialize_the_resource()
global do_something_with_lazy_initialization
do_something_with_lazy_initialization = actually_doing_something
actually_doing_something()
