Question

So I am converting some code from IDL to python. In the IDL there are about 50 variables held in a structure of structures;

values = { struct1: {a = 1, b = 2}, struct2: {a = 3, b = 4} ... etc }

The data can be accessed as follows:

print, values.struct1.a
# 1

Is there an easy way to do this in python where I can still have methods in the class values that act on the inner classes? For instance, having one setValues method that can change values in struct1 or struct2? I was hoping for something like this:

class values:
    def __init__(self):
         self.struct1 = self.struct1()
         self.struct2 = self.struct2()

    class struct1:
         def __init__(self):
             self.a = 1
             self.b = 2
    class struct2: 
         def __init__(self):
             self.c = 3
             self.d = 4

    def setValues(self, **kwargs):
        for key,value in kwargs.items():
             setattr(self, key, value)
        return

Where I could execute the following code:

st = values()
st.setValue(struct1.a = 2.0, struct2.a = 5.0)
print, st.struct1.a , st.struct2.a
# 2.0
# 5.0

but I get the following error:

AttributeError: values instance has no attribute 'struct1'

I am pretty new to python and was curious if anyone had some insight on a better way to produce a nested class and have methods that can act on all nests.

Was it helpful?

Solution

Having the code:

class values:

    class struct1:
         def __init__(self):
             self.a = 1
             self.b = 2

    class struct2: 
         def __init__(self):
             self.c = 3
             self.d = 4

    def __init__(self):
         self.struct1 = self.struct1()
         self.struct2 = self.struct2()

    def setValue(self, **kwargs):
        for key, value in kwargs.items():
            try:
                getattr(self.struct1, key)
            except AttributeError:
                # self.struct1 don't have any attribute which name is the value of 'key'.
                pass
            else:
                setattr(self.struct1, key, value)

            try:
                getattr(self.struct2, key)
            except AttributeError:
                # self.struct2 don't have any attribute which name is the value of 'key'.
                pass
            else:
                setattr(self.struct2, key, value)

You can:

>>> st = values()
>>> st.struct1.a = 10
>>> st.struct2.c = 20
>>> print(st.struct1.a)
>>> 10
>>> print(st.struct2.c)
>>> 20
>>> st.setValue(b=20, a=100, d=50, c=60)
>>> print(st.struct1.a)
>>> print(st.struct1.b)
>>> print(st.struct2.c)
>>> print(st.struct2.d)
>>> 100
>>> 20
>>> 60
>>> 50

EDIT: In your original question you had __init instead __init__ and:

self.struct1 = self.struct1()
self.struct1 = self.struct2()   # Here you was redefining self.struct1

I changed to:

self.struct1 = self.struct1()
self.struct2 = self.struct2()
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