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Using attrs for everything in Python

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Re: Using attrs for everything in Python

#3

Post by maxerickson »

jgalt212 wrote: post #2

This seems nice, but other than easy destructuring of functions that return long tuples (which really should return dicts), I cannot figure out a good use case for it over using a dictionary. I am keen to hear others' opinions.

A class with more methods than the Point3d example.

Re: Using attrs for everything in Python

#4

Post by whalesalad »

This is how I develop in Python. I do not use this helper library (and will certainly look into it), but definitely wish that more Python hackers built software in this way. Passing plain-old classes around that are very small and close to their domain is hugely valuable. Adding convenience methods or synthetic properties with a @property decorator is also hugely important. It lends itself to a very nice DSL where, for example, you can have image.png where the png property is a literal PNG representation of the image.

Re: Using attrs for everything in Python

#7

Post by japhyr »

Would there be any value to allowing a convention for the __init__() method that allows direct assignment of arguments to attributes? For example, replacing the following:

    class Point3D(object):
        def __init__(self, x, y, z):
            self.x = x
            self.y = y
            self.z = z
with:

    class Point3D(object):
        def __init__(self, self.x, self.y, self.z):
            # Other initialization work
It seems __init__ could be made to parse the list of parameters, and for any self.foo that's not defined, assign the corresponding argument to that attribute. But I have no experience in language design. Is there a reason this wouldn't work?

Re: Using attrs for everything in Python

#8

Post by m_ke »

japhyr wrote: post #7

Would there be any value to allowing a convention for the __init__() method that allows direct assignment of arguments to attributes? For example, replacing the following: class Point3D(object): def __init__(self, x, y, z): self.x = x self.y = y self.z = z with: class Point3D(object): def __init__(self, self.x, self.y, self.z): # Other initialization work It seems __init__ could be made to parse the list of parameter…

you can just do

  class B:
      def __init__(self, a, b, c):
          self.__dict__.update(locals())

Re: Using attrs for everything in Python

#10

Post by mkolodny »

While the conciseness of attrs is nice, it's not very readable.

This:

    class Point3D(object):
        def __init__(self, x, y, z):
            self.x = x
            self.y = y
            self.z = z
...is much easier to read than this:

    import attr
    @attr.s
    class Point3D(object):
        x = attr.ib()
        y = attr.ib()
        z = attr.ib()
Readability is what I love about Python. I don't think the conciseness of attrs is worth the loss in readability.
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