Returning each item from a list (Python)
I know that a function can return multiple values in Python. What I would like to do is return each item in the list as a separate return value. This can be an arbitrary number of items, depending on user input. I'm wondering if there is a pythonic way to do this?
For example, I have a function that will return a couple of items as an array, for example will return [a, b]
.
However, depending on the input entered, the function can generate multiple pairs, which will cause the function to return [[a, b], [c, d], [e, f]]
. Instead, I would like it to return[a, b], [c, d], [e, f]
At the moment I have implemented a very crappy function with a lot of temporary variables and counts, and I am looking for a cleaner suggestion.
Appreciate help!
source to share
There is a yield statement that is perfect for this utility.
def foo(a):
for b in a:
yield b
This returns a generator that you can iterate through.
print [b for b in foo([[a, b], [c, d], [e, f]])
source to share
When python function is executed:
return a, b, c
what it actually returns is a tuple (a, b, c)
, and tuples are unpacked on assignment, so you can say:
x, y, z = f()
and everything's good. Therefore, if you have a list
mylist = [4, "g", [1, 7], 9]
Your function can simply:
return tuple(mylist)
and behave as you expect:
num1, str1, lst1, num2 = f()
will perform tasks as you expect.
If you really want the function to return an indefinite number of things as a sequence that you can iterate over, then you will want to make it a generator with yield
but a different ball of wax.
source to share
Check out this question: How to return multiple values from * args?
The important idea is that the return values, if they are a container, can be expanded into separate variables.
source to share
However, depending on the input entered, the function can create multiple pairs, which will result in the function returning [[a, b], [c, d], [e, f]]. Instead, I would like it to return [a, b], [c, d], [e, f]
Can't you use the returned list (ie the list [[a, b], [c, d], [e, f]]) and extract the elements from it? Seems to fit your criteria for an arbitrary number / multiple values.
source to share