local variable 'allLibrary' referenced before assignment

Question

I can't seen to understand what the issue here is, I am getting an error that local variable 'allLibrary' referenced before assignment, Please help

@app.route('/', methods =['GET','POST'])
def add():
    if request.method =='POST':
        bookName=(request.form['bookName'])
        authorName =(request.form['author'])
        genre = request.form['type']
        library = library(bookName=bookName, authorName=authorName, genre = genre)
        db.session.add(library)
        db.session.commit()    
    allLibrary = library.query.all()
    
    return render_template('index.html', allLibrary=allLibrary) 

Answer 1

The UnboundLocalError: local variable referenced before assignment error is raised when you try to assign a value to a local variable before it has been declared. You can solve this error by ensuring that a local variable is declared before you assign it a value.

So to fix this make sure that the allLibrary variable is declared before you're accessing it. It could also be a Scope problem.

However it would seem that library is not assigned a value if the if statement fails, so you should probably ensure that that is within scope as well.