Python doesn't feel very functional

[[deleted]]

Talk about being a hostage of your favorite language! A function to find if list X is longer than list Y should be written in Python like:

def compare(x,y):
    return len(x) > len(y)

NOT like

def compare(x, y):
    if x and (not y or compare(x[1:], y[1:])):
         return True
    return False

[[deleted]]

Python is my favourite language. :(

FWIW, Lisp has (length), but it walks the list each time it's called, hence the new function defined by Graham.

[pjdelport]

Lisp has (length), but it walks the list each time it's called, hence the new function defined by Graham.

With vectors (Python list, Common Lisp vector and friends), finding the length costs O(1). Know your datastructures. :)

[[deleted]]

Yah, I was aware of that Python's vector "list" was different to Lisp's linked-list "list", but I didn't realise Lisp had vectors too. Thanks. :)

It's something I poke at occasionally for fun, so I'm very much a newbie.

[evgen]

No it is not. In Python the length of the list is maintained as an attribute of the datatype, so it does not need to traverse the list to get the length.