how can i know if a python object have a attribute such as 'attr1'?
for example, i may define a python class: class A: def sayHello(): print 'hello' a = A() a.attr1 = 'hello' a.attr2 = 'bb' b = A() a.attr2 = 'aa' how can i know whether an object have an attribute named attr1? -- View this message in context: http://old.nabble.com/how-can-i-know-if-a-python-object-have-a-attribute-such-as-%27attr1%27--tp27286937p27286937.html Sent from the Python - python-list mailing list archive at Nabble.com. -- http://mail.python.org/mailman/listinfo/python-list
how to generate random numbers that satisfy certain distribution
such as uniform distribution, Normal distribution or poisson distribution. is there any package that can be used to generate such random numbers. -- View this message in context: http://old.nabble.com/how-to-generate-random-numbers-that-satisfy-certain-distribution-tp27288180p27288180.html Sent from the Python - python-list mailing list archive at Nabble.com. -- http://mail.python.org/mailman/listinfo/python-list
Re: how to generate random numbers that satisfy certain distribution
Bugzilla from ra.ravi@gmail.com wrote: > > On Jan 23, 10:37 pm, thinke365 wrote: >> such as uniform distribution, Normal distribution or poisson >> distribution. >> is there any package that can be used to generate such random numbers. >> >> -- >> View this message in >> context:http://old.nabble.com/how-to-generate-random-numbers-that-satisfy-cer... >> Sent from the Python - python-list mailing list archive at Nabble.com. > > Did you try random package? > -- > http://mail.python.org/mailman/listinfo/python-list > > of course i have tried random package, but can this package generate random sequence that satisfy possion distribution , normal distribution and uniform distribution -- View this message in context: http://old.nabble.com/how-to-generate-random-numbers-that-satisfy-certain-distribution-tp27288180p27288996.html Sent from the Python - python-list mailing list archive at Nabble.com. -- http://mail.python.org/mailman/listinfo/python-list
this customize sort did not work ,what's wrong?
l = list() l1 = list((1, 2, 3, 4)) l2 = list((1,2)) l3 = list((1, 2, 3, 4, 5)) l.append(l1) l.append(l2) l.append(l3) print l def sort_by_list(E1, E2): print len(E1), len(E2) return len(list(E1)) > len(list(E2)) l.sort(cmp=sort_by_list) print l output: [[1, 2, 3, 4], [1, 2], [1, 2, 3, 4, 5]] 2 4 5 2 [[1, 2, 3, 4], [1, 2], [1, 2, 3, 4, 5]] the order of the elements in the list did not change! -- View this message in context: http://old.nabble.com/this-customize-sort-did-not-work-%2Cwhat%27s-wrong--tp27289860p27289860.html Sent from the Python - python-list mailing list archive at Nabble.com. -- http://mail.python.org/mailman/listinfo/python-list
Re: this customize sort did not work ,what's wrong?
i mean the output i want is: [ [1, 2], [1, 2, 3, 4], [1, 2, 3, 4, 5]], that is sort according to the length of the list element thinke365 wrote: > > l = list() > l1 = list((1, 2, 3, 4)) > l2 = list((1,2)) > l3 = list((1, 2, 3, 4, 5)) > l.append(l1) > l.append(l2) > l.append(l3) > print l > > def sort_by_list(E1, E2): > print len(E1), len(E2) > return len(list(E1)) > len(list(E2)) > > l.sort(cmp=sort_by_list) > print l > > output: > [[1, 2, 3, 4], [1, 2], [1, 2, 3, 4, 5]] > 2 4 > 5 2 > [[1, 2, 3, 4], [1, 2], [1, 2, 3, 4, 5]] > > the order of the elements in the list did not change! > -- View this message in context: http://old.nabble.com/this-customize-sort-did-not-work-%2Cwhat%27s-wrong--tp27289860p27289922.html Sent from the Python - python-list mailing list archive at Nabble.com. -- http://mail.python.org/mailman/listinfo/python-list
Re: this customize sort did not work ,what's wrong?
jesus, now i fixed it, using odd lambda sort. l.sort(lambda x,y: cmp(len(x), len(y))) print l BUT I AM STILL CONFUSED WHY COSTOMIZED SORT FAILED TO SORT AS IT IS PROGRAMMER! thinke365 wrote: > > i mean the output i want is: > [ [1, 2], [1, 2, 3, 4], [1, 2, 3, 4, 5]], that is sort according to the > length of the list element > > thinke365 wrote: >> >> l = list() >> l1 = list((1, 2, 3, 4)) >> l2 = list((1,2)) >> l3 = list((1, 2, 3, 4, 5)) >> l.append(l1) >> l.append(l2) >> l.append(l3) >> print l >> >> def sort_by_list(E1, E2): >> print len(E1), len(E2) >> return len(list(E1)) > len(list(E2)) >> >> l.sort(cmp=sort_by_list) >> print l >> >> output: >> [[1, 2, 3, 4], [1, 2], [1, 2, 3, 4, 5]] >> 2 4 >> 5 2 >> [[1, 2, 3, 4], [1, 2], [1, 2, 3, 4, 5]] >> >> the order of the elements in the list did not change! >> > > -- View this message in context: http://old.nabble.com/this-customize-sort-did-not-work-%2Cwhat%27s-wrong--tp27289860p27290014.html Sent from the Python - python-list mailing list archive at Nabble.com. -- http://mail.python.org/mailman/listinfo/python-list
