On May 11, 4:32 pm, Grant Edwards <[EMAIL PROTECTED]> wrote: > On Fri, May 11, 2007 at 01:20:44PM -0700, [EMAIL PROTECTED] > wrote: > > > On May 11, 3:55 pm, Grant Edwards <[EMAIL PROTECTED]> wrote: > > > You got those results because that's what your program does. > > > > Were you intending it to do something else? If so, you're > > > going to have to explain what you wanted, because we can't > > According to my output, it seems that arg is False even when I > > give an option of '-o' which according to the book should be > > True. No? > > '-o' is not equal to True. However, that does not mean it > evaluates to false when tested by an if or while statement. > > > If arg == ['-o'] then shouldn't arg == True return True and > > skip the if? > > No. See the folloing link regarding the "truth value" of an > object: > > http://docs.python.org/lib/truth.html > > There are many objects other than True that evaluate to "true" > in the context of an if/while statement. Just because an > objecty has a "true" truth-value doesn't mean that it is equal > to the True object. > > -- > Grant Edwards grante Yow! Why don't you ever > at enter any CONTESTS, > visi.com Marvin?? Don't you know > your own ZIPCODE?
OK. Then how would you differenciate between a call with an option versus one without (e.g. help.py -o (where arg == ['-o']) Vs. help.py (where arg == []))? -- http://mail.python.org/mailman/listinfo/python-list
