Python if vs try-except

Question

I was wondering why the try-except is slower than the if in the program below.

def tryway():
    try:
        while True:
            alist.pop()
    except         


        

Answer 1

If you are really interested in speed, both of your contestants could do with losing some weight.

while True: is slower than while 1: -- True is a global "variable" which is loaded and tested; 1 is a constant and the compiler does the test and emits an unconditional jump.

while True: is redundant in ifway. Fold the while/if/break together: while alist != []:

while alist != []: is a slow way of writing while alist:

Try this:

def tryway2():
    alist = range(1000)
    try:
        while 1:
            alist.pop()
    except IndexError:
        pass

def ifway2():
    alist = range(1000)
    while alist:
        alist.pop()

`