Viraj's Weblog

I've always found the reverse() method of a list rather wierd because it reverses the list in place. I just found out about reversing via slicing:

>>> f=['foo', 'bar', 'baz']
>>> f[::-1]
['baz', 'bar', 'foo']
>>> f='hello'
>>> f[::-1]
'olleh'

There is also a new builtin function in 2.4 called reversed(), which returns an iterator, and is more efficient for large lists:

>>> f=['foo', 'bar', 'baz']
>>> for x in reversed(f):
...   print x
... 
baz
bar
foo

And yet another (ugly) method shown to me by a coworker:

>>> f=['foo', 'bar', 'baz']
>>> reduce(lambda x,y: [y] + ((type(x) == type([]))
...        and x or [x]), f)
['baz', 'bar', 'foo']

Hmm, Python seems to be moving towards TMTOWTDI.