I know I can get a Class's attributes with a string like this:
object.attribute = 'foo'
x = 'attribute'
getattr(object, x)
>>> 'foo'
Is there a way to "go deeper" into the object's attributes with a string? In other words, if my object contains another object, how can I get the the sub-object's attributes with a string? For example:
object.object.attribute
The operator.attrgetter function does this:
class Foo: pass
f = Foo()
f.bar = Foo()
f.bar.baz = Foo()
f.bar.baz.quux = "Found me!"
import operator
print operator.attrgetter("bar.baz.quux")(f) # prints "Found me!"
I love the recipe given in this link (actually the comment is even better though)
Example borrowed from Claudiu's answer (which is great too):
class Foo: pass
f = Foo()
f.bar = Foo()
f.bar.baz = Foo()
f.bar.baz.quux = "Found me!"
A recursive getattr that follows dots:
>>> rgetattr = lambda o,a: reduce(getattr, a.split('.'), o)
>>> rgetattr(f, 'bar.baz.quux')
'Found me!'
The non-lambda version being:
def rgetattr(obj, attr):
return reduce(getattr, attr.split('.'), obj)
>>> class Foo: pass
>>> f = Foo()
>>> f.bar = Foo()
>>> f.bar.baz = Foo()
>>> f.bar.baz.quux = "Found me!"
>>> getattr(f, 'bar')
<__main__.Foo instance at 0x01EC5918>
>>> getattr(getattr(f, 'bar'), 'baz')
<__main__.Foo instance at 0x01EC5A30>
>>> getattr(getattr(getattr(f, 'bar'), 'baz'), 'quux')
'Found me!'
EDIT: Done as a simple method:
>>> def dynamic_lookup(obj, dot_attrs):
attr_list = dot_attrs.split(".")
while attr_list:
obj = getattr(obj, attr_list.pop(0))
return obj
>>> f
<__main__.Foo instance at 0x01EC50A8>
>>> dynamic_lookup(f, 'bar.baz.quux')
'Found me!'
Easily adaptable to take a list of strings (take attr_list directly instead of dot_attrs), but I thought the . notation as a string would look cooler...
