This is very fancy but extremely hard to comprehend :) If this is the best that we can do, perhaps add a sample of what the output would be? I must tell you, even running the code, the output is still very confusing:

```python
In [43]: repos_tree
Out[43]: defaultdict(<functools.partial object at 0x107c1baf8>, {'rhel': defaultdict(<functools.partial object at 0x107c1baa0>, {'rhct6': defaultdict(<functools.partial object at 0x107c1ba48>, {'rhct65': defaultdict(<type 'str'>, {'rhct65_a': 'x86_64', 'rhct65_v': '6.5', 'rhct65_n': 'Red Hat CloudForms Tools for RHEL 6 RPMs x86_64 6.5'}), 'rhct6S': defaultdict(<type 'str'>, {'rhct6S_a': 'x86_64', 'rhct6S_n': 'Red Hat CloudForms Tools for RHEL 6 RPMs x86_64 6Server', 'rhct6S_v': '6Server'})})})})

In [44]: repos_tree['rhel']
Out[44]: defaultdict(<functools.partial object at 0x107c1baa0>, {'rhct6': defaultdict(<functools.partial object at 0x107c1ba48>, {'rhct65': defaultdict(<type 'str'>, {'rhct65_a': 'x86_64', 'rhct65_v': '6.5', 'rhct65_n': 'Red Hat CloudForms Tools for RHEL 6 RPMs x86_64 6.5'}), 'rhct6S': defaultdict(<type 'str'>, {'rhct6S_a': 'x86_64', 'rhct6S_n': 'Red Hat CloudForms Tools for RHEL 6 RPMs x86_64 6Server', 'rhct6S_v': '6Server'})})})

In [45]: repos_tree['rhel']['rhct6']
Out[45]: defaultdict(<functools.partial object at 0x107c1ba48>, {'rhct65': defaultdict(<type 'str'>, {'rhct65_a': 'x86_64', 'rhct65_v': '6.5', 'rhct65_n': 'Red Hat CloudForms Tools for RHEL 6 RPMs x86_64 6.5'}), 'rhct6S': defaultdict(<type 'str'>, {'rhct6S_a': 'x86_64', 'rhct6S_n': 'Red Hat CloudForms Tools for RHEL 6 RPMs x86_64 6Server', 'rhct6S_v': '6Server'})})
``