Question

I have the Model Chapter:

class Chapter(ndb.Model):
    tutKey = ndb.KeyProperty(kind='Tutorial')
    title = ndb.StringProperty(required=True)
    content = ndb.TextProperty(required=True)
    note = ndb.TextProperty()
    lvl = ndb.IntegerProperty(default=0)
    order = ndb.IntegerProperty(default=0)
    parentID = ndb.KeyProperty(kind='Chapter')
    number = ndb.IntegerProperty()

‘number’ is the base chapter (chap1 or chap 1.2 have number = 1). ‘lvl’ is for the depth of the chapter, for example, in chap1.1.1 the lvl is 3 and in chap1.1.1.1 lvl is 4. And the ‘order’ says the order of the chap, for example, in chap1.2 ‘order’ is 2 and in chap2.2 ‘order’ is also 2.

How can i sort the following chapters (for example)?

chapter 2
chapter 2.1
chapter 1.1.1
chapter 1.1
chapter 1

I have been thinking… should i create a StringProperty to save the chapter number like “1.2.1” and then split the string by ‘.’ ?

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EDIT: i created a ndb.IntegerProperty(repeated=True) the equivalent to ListProperty suggested by JBernardo. I’m able to store the data correctly, but I can’t get a way to sort by the property. Anyone knows how to do this?

Answer 1

Found a simpler way to solve my problem.
I store the chapter in a different way. In ndb.IntegerProperty(repeated=True). This way i can sort it just my using:

newChaps = sorted(chaps, key=lambda obj: obj.version)

Where ‘version’ is the ndb.IntegerProperty.

Done.