if instance exists problem ..
steve at REMOVE-THIS-cybersource.com.au
Thu Oct 18 05:00:56 CEST 2007
On Wed, 17 Oct 2007 23:12:15 +0000, Paul Hankin wrote:
> 'if x' doesn't test if x exists, it tests if x when cast to a bool is
To be pedantic:
Python doesn't have type casts. bool(x) doesn't cast x as a bool, it
creates a brand new Boolean object from x.
Also, the "if x" test looks at x.__nonzero__() first, and if that method
doesn't exist, it looks to see if x.__len__() returns 0 or not. See
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