python - 在python中遍历对象

Question

如何编写这段代码而不是无限期地重复自己？

fields = row.split('__')

if len(fields) == 1:
    foo = getattr(bundle.obj, fields[0])
elif len(fields) == 2:
    foo = getattr(getattr(bundle.obj, fields[0]), fields[1])
elif len(fields) == 3:
    foo = getattr(getattr(getattr(bundle.obj,
                            fields[0]), fields[1]), fields[2])
# etc ..

Answer 1

使用reduce() :

foo = reduce(getattr, fields, bundle.obj)

或者一个简单的循环:

foo = bundle.obj
for field in fields:
    foo = getattr(foo, field)