os.walk walks too much
jepler at unpythonic.net
Fri Feb 27 22:04:49 CET 2004
On Fri, Feb 27, 2004 at 02:51:04PM -0500, Marcello Pietrobon wrote:
> dirs[:] creates a copy of dirs
This creates a new list which contains the same items as the list named
> dirs[:] =  - empty the original list
This changes the items in the list named by dirs. It replaces (mutates)
the range named on the left-hand of = with the items on the right-hand.
> dirs =  - empty a copy of the original list
This makes dirs name a different list than it did before, but the value
of the list that dirs named a moment ago is unchanged.
In the case of os.walk (or anywhere you do something by mutating an item
passed in) you have to change the items in a particular list ("mutate
the list") , not change the list a particular local name refers to.
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