This has nothing with Web2py but with Python. Try this: >>> a = 5 >>> def f(): if False: a = 3 return a >>> f() UnboundLocalError: local variable 'a' referenced before assignment
And this is exactly what you have in vote_callback() with variable books. Python can with variables from outer scope work and use them readonly. However here Python will determine that 'books' (or 'a') is readwrite - and you haven't set it yet (if condition 'vars and auth_user' is False) and you want get its value (in 'return' command). On Monday, 20 March 2017 14:38:38 UTC+1, Joe Dunst wrote: > > > I'm trying to make a "vote up" and "vote down" feature in my program, like > the one in reddit.com. But I've been receiving tickets from 2 different > errors. (I solved the first one but I want to > First, I received a "UnboundLocalError: local variable 'books' referenced > before assignment" > This was my code at the time when I had that error. > *CONTROLLER: * > def vote_callback(): > vars = request.post_vars > if vars and auth_user: > *id = vars.id <http://vars.id>* > direction = +1 if vars.direction == 'up' else -1 > *books = db.books(id)* > if books: > votes = db.votes(post=id, created_by=auth.user.id) > if not votes: > books.update_record(vote_book=books.book_vote+direction) > db.votes.insert(post=id,score=direction) > elif votes.score!=direction: > books.update_record(vote_book=books.book_vote+direction) > votes.update_record(score=direction) > else: > pass > print books.book_vote > return str(books.book_vote) > > > *VIEW:* > <head> > <script type = "text/javascript" src = " > https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js > "></script> > > </head> > <body> > > <h1>This is the default/list_books_by_vote.html template</h1> > > {{if request.function=='list_books_by_vote':}} > {{=A('sort by datetime', _class='btn', > _href=URL('list_books_by_datetime'))}} > > {{elif request.function=="list_books_by_datetime":}} > {{=A('sort by votes', _class='btn', _href=URL('list_books_by_vote'))}} > > {{else:}} > <h1> > {{=author(user_id)}} > </h1> > {{pass}} > > {{for post in rows:}} > <div class="well"> > <table> > <tr *data-id="{{=post.id <http://post.id>}}"*> > <td> > <button *data-direction="down"* class="btn btn-primary"> > Remove vote > </button> > </td> > <td> > <span *class="votes"*> > *{{=post.book_vote}}* > </span> > </td> > <td> > <button *data-direction="up"* class="btn btn-success" > style="margin-left:5px;margin-right:5px;"> > I referenced this! > </button> > </td> > <td> > <strong>{{=A(post.book_title, > _href=URL('show_specific_user', args=post.id))}}</strong> > </td> > <td> > <span> > {{=author(post.modified_by)}} > </span> > </td> > </tr> > </table> > </div> > {{pass}} > > *<script type = "text/javascript">* > * function do_ajax_vote(t, direction) {* > * var id = jQuery(t).closest('tr').attr('data-id');* > * jQuery.ajax({method:'post',url:'{{=URL('vote_callback')}}',* > * data:{'id':id,'direction':direction},* > * success: function(data){* > * > jQuery(t).closest('tr').find('.votes').html(data);* > * } });* > * }* > > * jQuery(function() {* > * jQuery('[data-direction=up]').click(function(){do_ajax_vote(this, > 'up');});* > * > jQuery('[data-direction=down]').click(function(){do_ajax_vote(this, > 'down');});* > * });* > *</script>* > </body> > > > *Model:* > db.define_table('books', > Field('book_title', 'string', > requires=(IS_NOT_IN_DB(db,'books.book_title'), IS_NOT_EMPTY()), > label='Thesis Title'), > Field('book_subtitle', 'string', label='Thesis Subtitle > (Optional)'), > Field('book_date', type='date', requires=IS_DATE(), > label='Publish Date' ), > Field('book_abstract', type='text', > requires=IS_NOT_EMPTY() , label='Thesis Abstract' ), > Field('book_school', requires=IS_IN_SET(['AMA Computer > College - Naga Campus', 'Ateneo de Naga University', 'Naga College > Foundation', 'Computer Communication Development Institute', 'University of > Nueva Caceres']), label='Orginating School' ), > Field('book_location', requires=IS_IN_SET(['AMA Computer > College - Naga Campus', 'Ateneo de Naga University', 'Naga College > Foundation', 'Computer Communication Development Institute', 'University of > Nueva Caceres']), label='Location' ), > Field('book_proponents', requires=IS_NOT_EMPTY(), > label='Thesis Proponents' ), > Field('book_category', requires=IS_IN_SET(['Education, > Science and Teacher Training', 'Fine and Applied Arts', 'Humanities', > 'Religion and Theology', 'Social Behavioral Sciences', 'Business > Administration and Related', 'Law and Jurispusence', 'Natural Science', > 'Mathematics', 'IT-Related Disciplines', 'Engineering and Tech', 'Medical > and Allied', 'Trade, Craft and Industrial', 'Architecture and Town > Planning', 'Agriculture, Forestry, Fisheries', 'Home Economics', 'Service > Trades', 'Mass Communication and Documentation', 'Maritime', 'General', > 'Other Disciplines']), label='Thesis Category' ), > Field('book_level', requires=IS_IN_SET(['Undergraduate', > 'Masteral']), label='Thesis Level' ), > Field('book_course', requires=IS_IN_SET(['Bachelor of > Science in Information Technology', 'Bachelor of Science in Computer > Science']), label='Proponent\'s Course' ), > * Field('book_vote', 'integer', default=0, readable=True, > writable=True),* > auth.signature > ) > > *db.define_table('votes',* > * Field('books', 'reference books'),* > * Field('score', 'integer', default=+1),* > * auth.signature* > * )* > > I "solved" the problem when I searched the internet and saw this " > http://stackoverflow.com/questions/15217145/local-variable-author-referenced-before-assignment";. > > I learned that I should transfer these lines: > > *id = vars.id <http://vars.id>* > *books = db.books(id)* > outside of the loop. I did that so I'm not getting that error anymore. > > > > Now, I'm getting another error when I transfered the two varianles outside > the loop. I tried looking for answers in the internet to no avail. > The error is: UnboundLocalError: local variable 'books' referenced before > assignment > > *CONTROLLER: * > def vote_callback(): > vars = request.post_vars > *id = vars.id <http://vars.id>* > * books = db.books(id)* > if vars and auth_user: > direction = +1 if vars.direction == 'up' else -1 > if books: > votes = db.votes(post=id, created_by=auth.user.id) > if not votes: > books.update_record(vote_book=books.book_vote+direction) > db.votes.insert(post=id,score=direction) > elif votes.score!=direction: > books.update_record(vote_book=books.book_vote+direction) > votes.update_record(score=direction) > else: > pass > print books.book_vote > return str(books.book_vote) > > > *VIEW:*The same > > > *Model:*The same > > P.S. > -I highlighted the relevant parts of the code. > -The View and the Model is working. I think the problem with the code is > in the controller. > -I'm trying to do this at 27:58 > https://www.youtube.com/watch?v=DIOFcDIlHWI&index=3&list=PLG0pjuN991OmU891IjbxOss3kYEz_JMR7 > > > *Thanks in advance.* > -- Resources: - http://web2py.com - http://web2py.com/book (Documentation) - http://github.com/web2py/web2py (Source code) - https://code.google.com/p/web2py/issues/list (Report Issues) --- You received this message because you are subscribed to the Google Groups "web2py-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to web2py+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
