Arnaud Delobelle wrote: > On Feb 8, 5:20 pm, "Reedick, Andrew" <[EMAIL PROTECTED]> wrote: >> > -----Original Message----- >> > From: [EMAIL PROTECTED] [mailto:python- >> > [EMAIL PROTECTED] On Behalf Of c james >> > Sent: Friday, February 08, 2008 12:10 PM >> > To: [EMAIL PROTECTED] >> > Subject: keyword 'in' not returning a bool? >> >> > Try this >> >> > >>> sample = {'t':True, 'f':False} >> > >>> 't' in sample >> > True >> > >>> type('t' in sample) >> > <type 'bool'> >> > >>> 't' in sample == True >> > False >> >> > Why is this? Now try >> > >>> bool('t' in sample) == True >> > True >> >> > Can someone explain what is going on? >> >> >>> ('t' in sample) == True >> >> True >> >> It's operator precedence. 'in' has lower precedence than '=='. Therefore >> 't' in sample == True >> evaluates as >> 't' in (sample == True) >> >> The real question is why does >> 't' in (sample == True) >> cause an error: >> TypeError: argument of type 'bool' is not iterable >> while >> 't' in sample == True >> does not? > > That should have told you precedence is not the reason!
I would guess that it is the same reason that: 1 <= (2 < 3) is different than: 1 <= 2 < 3 Condition-chaining, I think its called, though I might be wrong. > > -- > Arnaud -- http://mail.python.org/mailman/listinfo/python-list
