emptying a list

[lallous]

Hello

What is faster when clearing a list?

del L[:]

or

L = []

 

[Geoffrey Clements]

Hello

What is faster when clearing a list?

del L[:]

or

L = []

Oh, "L = []" definitely, on the basis that there are fewer characters to
type.


http://docs.python.org/3.1/library/profile.html

 

[Jon Clements]

Hello

What is faster when clearing a list?

del L[:]

or

L = []

Does it really matter that much?

And you're really talking about two different things, which quite
often come up on this group.

Example follows:

x = range(5)
x = y
print x, y [1, 2, 3, 4] [1, 2, 3, 4]
x = []
print x, y [] [1, 2, 3, 4]
x = y
print x, y [1, 2, 3, 4] [1, 2, 3, 4]
del x[:]
print x, y

[] []

Cheers,
Jon.

 

[Simon Forman]

Hello

What is faster when clearing a list?

del L[:]

or

L = []

The first form actually clears the list, the second for just re-binds
the name 'L' to a new, empty list.