On Wed, Nov 07, 2018 at 02:48:40PM +0000, Albert-Jan Roskam wrote:
> What is the best way to dynamically set class variables? I am looking
> for a generalization of something like this:
>
> class Parent: pass
> class Child(Parent):
> col1 = 'str'
> col2 = 'int'
The obvious solution is to do exactly that: just set the class attribute
in the subclass. If the value is dynamically generated, so be it:
class Child(Parent):
col1 = calculate_some_value()
col2 = col1 + calculate_something_else()
If the names of the class attributes themselves have to be generated,
that's what locals() is for:
class Child(Parent):
for i in range(10):
name = "column" + str(i)
locals()[name] = i
del i
will give you class attributes column0 = 0, column1 = 1, etc. Of course
you can generate the names any way you like, e.g. read them from a text
file.
A cleaner solution might be to move the code into a function and pass
the class namespace to it:
def make_attrs(ns):
for i in range(10):
name = "column" + str(i)
ns[name] = i
class Child(Parent):
make_attrs(locals())
assert column0 == 0
assert Child.column1 == 1
Does this help?
--
Steve
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