On Monday, July 16, 2012 8:45:51 PM UTC-5, rusi wrote:
> On Jul 15, 9:50 pm, Rick Johnson <rantingrickjohn...@gmail.com> wrote:
> > I think this issue is not so much a "bool test" vs "type
> > test", but more an ambiguous syntax issue.
> >
>
> If you know some English, its clear that if and while
> create bool contexts.
Wrong. "if and "while" do not /create/ anything. On a syntactical level they
merely /suggest/ to the reader that the following statement is expected to be a
boolean value. It is the /statement/ itself that creates the boolean value, not
the keywords!
Observe:
0 == 0 -> True
isinstance("5", int) -> False
You see, "if" and "while" don't create anything, in reality they merely execute
a block of code depending on the value of the statement that follows the
keyword. "if" and "while" are only *logical switches* and nothing more. You
could write a simple quasi-example of "if" as a function like this:
def if_(value):
if not value:
return
# do_something_here
Those previous statements where /explicit/, and as such need no bool() function
to resolve their Boolean values, however, consider the following /implicit/
conversions to Boolean:
[] -> False
[1] -> True
"" -> False
"1" -> True
0 -> False
1 -> True
2 -> True
etc...
It is my strong opinion that these types of implicit conversions are evil
obfuscations of the truth. If we want to convert an object to a Boolean, then
use the bool() function on that object:
bool([]) -> False
bool([1]) -> True
etc...
Heck! Why even have a damn bool function if you're never going to use it?
> [If you know English but have not
> studied logic the 'if/while' make sense whereas 'bool' is
> gobbledygook]
And which Univeristy would you recommend for studying the intricacies of
"gobbledygook"? ;-)
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