??? 123123123123 .....................................................................................................................................??? 123123123123 .....................................................................................................................................ó ¿œ^c@sNdZd„Zd„Zddd„ƒYZd„ZedkrJeƒndS( s Example of a generator: re-implement the built-in range function without actually constructing the list of values. OldStyleRange is coded in the way required to work in a 'for' loop before iterators were introduced into the language; using __getitem__ and __len__ . cCsÞyºt|ƒdkr,dt|dƒdfSt|ƒdkr_t|dƒt|dƒdfSt|ƒdkr¤|ddkrtdƒ‚ntd„|DƒƒStdt|ƒƒ‚Wntk rÙtdƒ‚nXd S( sgTake list of arguments and extract/create proper start, stop, and step values and return in a tupleiiiisstep argument must not be zerocss|]}t|ƒVqdS(N(tint(t.0tx((s*/usr/lib64/python2.7/Demo/classes/Range.pys ss$range() accepts 1-3 arguments, givensArange() arguments must be numbers or strings representing numbersN(tlenRt ValueErrorttuplet TypeError(targlist((s*/usr/lib64/python2.7/Demo/classes/Range.pyt handleargss! cgsAt|ƒ\}}}|}x||kr<|V||7}qWdS(s,Function to implement 'range' as a generatorN(R(tatstarttstoptsteptvalue((s*/usr/lib64/python2.7/Demo/classes/Range.pytgenranges toldrangecBs2eZdZd„Zd„Zd„Zd„ZRS(sClass implementing a range object. To the user the instances feel like immutable sequences (and you can't concatenate or slice them) Done using the old way (pre-iterators; __len__ and __getitem__) to have an object be used by a 'for' loop. cGsEt|ƒ\|_|_|_td|j|j|jƒ|_dS(s„ Initialize start, stop, and step values along with calculating the nubmer of values (what __len__ will return) in the rangeiN(RR R R tmaxR(tselfR ((s*/usr/lib64/python2.7/Demo/classes/Range.pyt__init__,scCsd|j|j|jfS(s-implement repr(x) which is also used by printsrange(%r, %r, %r)(R R R (R((s*/usr/lib64/python2.7/Demo/classes/Range.pyt__repr__2scCs|jS(simplement len(x)(R(R((s*/usr/lib64/python2.7/Demo/classes/Range.pyt__len__6scCs>d|ko|jknr1|j|j|Std‚dS(simplement x[i]isrange[i] index out of rangeN(RR R t IndexError(Rti((s*/usr/lib64/python2.7/Demo/classes/Range.pyt __getitem__:s(t__name__t __module__t__doc__RRRR(((s*/usr/lib64/python2.7/Demo/classes/Range.pyR"s    c Cs9ddl}ddl}|jdddƒ}ttdddƒƒ}ttdddƒƒ}||ksu||kr‘td|||fƒ‚ndGH|jƒ}xtdƒD]}q¯W|jƒ}xtdƒD]}qÒW|jƒ}x|jdƒD]}qøW|jƒ} ||GdGH||Gd GH| |Gd GHdS( NiÿÿÿÿiidisEerror in implementation: correct = %s old-style = %s generator = %ssTimings for range(1000):ièssec (old-style class)ssec (generator)ssec (built-in)(ttimet __builtin__trangetlistRRt Exception( RRtcorrect_resulttoldrange_resulttgenrange_resulttt1Rtt2tt3tt4((s*/usr/lib64/python2.7/Demo/classes/Range.pyttestBs*      t__main__N((RRRRR'R(((s*/usr/lib64/python2.7/Demo/classes/Range.pyts