I have python variables as given below.
global a,b,c
i want to initialize all these variables with different values in a single statement.
is it possible?
a=b=c=uuid.uuid1() //should return different values for a,b and c
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2 Answers
Call uuid.uuid1() three times:
a, b, c = uuid.uuid1(), uuid.uuid1(), uuid.uuid1()
You could make that a loop, but for 3 fixed items, why bother? Moreover, for an unpacking assignment like this with just 2 or 3 elements, the CPython compiler optimizes the bytecode.
If you use a loop anyway (if you have a few more targets to assign to), use a generator expression and avoid creating a list object:
a, b, c, d, e, f, g, h = (uuid.uuid1() for _ in xrange(8))
answered Apr 22, 2014 at 11:31
Martijn Pieters
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Comments
You can do that using a generator as:
a,b,c = (uuid.uuid1() for _ in range(3))
It will be particularly useful when you have lots of variables to assign data to.
Example
a,b,c = (randint(1,10) for _ in range(3))
>>> print a,b,c
7 2 9
8 Comments
Martijn Pieters
If you use a loop, use a generator expression and avoid creating a list object.
user2357112
@MartijnPieters: Why bother? It's 3 items, and it's not like we can avoid having them all in memory at once (since they're immediately assigned to
a, b, and c). I think the generator object might actually be bigger than the list.Martijn Pieters
Just replace the
[..] square brackets with (..) parenthesis, see my answer.Martijn Pieters
@user2357112: It can never be 'bigger'; it could be slower to process, except that the exact same bytecode is executed. But minus creating a list object.
user2357112
@MartijnPieters: Bigger due to overhead like the frame object, which appears to be 432 bytes on my machine. Avoiding the creation of a 3-element list object doesn't seem worthwhile here.
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