[Tutor] Can I tell me anyone about [x.lower() for x in lst]

[alan.gauld@bt.com]

> >>> lst =3D ['ONE', 'TWO', 'THREE']
> >>> newlst =3D [x.lower() for x in lst]
>   File "<stdin>", line 1
>     newlst =3D [x.lower() for x in lst]
> 
> I am using python1.5 on Red Hat Linux 7.1.
> Does  the facility "[x.lower() for x in lst]" not 
> available in python1.5 ?

Correct. List comprehensions were introduced in version 2.0.

The equivalent code for 1.5 is:

lst = ['ONE', 'TWO', 'THREE']
newlst = map(string.lower, lst)

OR without a functional approach:

lst = ['ONE', 'TWO', 'THREE']
newlst = []
for x in lst: 
	newlst.append(string.lower(x))

Alan g