如何在django模型中修复“选择必须是可迭代的”错误？

Question

I'm trying to migrate my app to the database, but the error does not allow me Where I should make changes?

I have already looked through other Decisions. Nothing could help me

class Movie(models.Model):                              
        NON_RATED = 0                                   
        RATED_G = 1                                     
        RATED_PG = 2                                    
        RATED_R = 3                                     
        RATINGS = (                                    
            (0, 'NR-not_rated'),                        
            (1, 'G-General_Audiences'),                 
            (2, 'PG-Parental_Guidances', 'Suggested'),  
            (3, 'R-Restricted')                         
        )          
        rating = models.IntegerField(     
                choices=RATINGS,            
                default=0)   

Answer 1

Choices attribute takes a list or tuple of 2 pairs . You cannot have a third value as you have.

class Movie(models.Model):                              
        NON_RATED = 0                                   
        RATED_G = 1                                     
        RATED_PG = 2                                    
        RATED_R = 3                                     
        RATINGS = (                                    
            (0, 'NR-not_rated'),                        
            (1, 'G-General_Audiences'),                 
            (2, 'PG-Parental_Guidances', 'Suggested'),  # you should remove Suggested here. 
            (3, 'R-Restricted')                         
        )          
        rating = models.IntegerField(     
                choices=RATINGS,            
                default=0) 

If you want another one you can try (2, ('PG-Parental_Guidances', 'Suggested')) but this will also give an error in some default values because of the internal structure.