Thanks Tim,
That's actually the stuff I was trying to remember.
my_list = [name for _, name, _ in k]
I recalled using some underscores for nice dense unnamed variable
unpacking before, but couldn't recall the process.
Thanks for that.
Ross.
On 15-Sep-09, at 6:33 PM, Tim Chase wrote:
If I have a list of tuples:
k=[("a", "bob", "c"), ("p", "joe", "d"), ("x", "mary", "z")]
and I want to pull the middle element out of each tuple to make a new
list:
myList = ["bob", "joe", "mary"]
is there some compact way to do that? I can imagine the obvious one
of
myList = []
for a in k:
myList.append(a[1])
But I'm guessing Python has something that will do that in one
line...
To add some readability to the other suggested solutions, I'd use
tuple unpacking
my_list = [name for status, name, code in k]
Not knowing what [0] and [2] are, I randomly designated them as
"status" and "code", but you likely have your own meanings. If you
don't, you can always just use the "_" convention:
my_list = [name for _, name, _ in k]
# or
my_list = [name for (_, name, _) in k]
As an aside, "my_list" is preferred over "myList" in common Python
practice. I don't know if there's a preferred convention for "with
vs without" the parens in such a tuple-unpacking list comprehension.
-tkc
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