Hans Fangohr wrote: > Hi Kent, > >> Hans Fangohr wrote: >> >>> In [2]: 2 in [1,2,3] == True >>> Out[2]: False >>> >>> Why does [2] return False? Would people agree that this is a bug? >> No, not a bug. Don't be too quick to blame your tools! > > That's good news. I'd be worried if this wasn't the desired behaviour > -- I just hadn't understood the logic. > >> The equivalent expression is >> In [1]: (2 in [1,2,3]) and ([1,2,3]==False) >> Out[1]: False > > Ah -- that's the way to read it! > >> 'in' is considered a comparison operator and can be chained with other >> comparisons. For a clearer example, consider >> In [2]: 2 < 3 < 4 >> Out[2]: True >> >> which is not the same as >> In [3]: 2 < (3 < 4) >> Out[3]: False >> >> or >> In [4]: (2 < 3) < 4 >> Out[4]: True >> >> It is equivalent to >> In [5]: (2 < 3) and (3 < 4) >> Out[5]: True >> > > Well explained -- makes perfect sense now. >
Just one further question : >>> 1 == True True >>> 5 == True False and yet >>> if 5 : print 'True' True I thought a non-zero or non-empty was evaluated as True. Now in the 5 == True line I'm not saying "5 is True", shouldn't it evaluate just like the "if" statement? _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
