<p>Data:  a dependency list, already verified to be acyclic.  So here, 'a' depends on 'b','c' (c depends on d), etc...  </p>

<pre><code>A = { 'a' :  dict(b=1, c=1),
    'c' : dict(d=1),
    'd' : dict(e=1,f=1,g=1),
    'h' : dict(j=1)
    }
</code></pre>

<p>I'd like to have a top-down, recursive solution to let's say, find the chain starting at 
'a':  a, c, d, e, g, f, b</p>

<p>So, right now (a non-generator solution):</p>

<pre><code>def get_all(D,k):
    L = []
    def get2(D,k):
        L.append(k)
        for ii in D.get(k,[]):
            get2(D, ii)
    get2(D,k)
    return L
</code></pre>

<p>Obviously, this is pretty weak :)  I've been banging my head about how to how to get yields inside there, and I'd appreciate any py-foo y'all can bring to this.</p>

Try this:
```
```
#!/usr/bin/env python

def get_all(D, k):
    yield k
    for ii in D.get(k, []):
        for jj in get_all(D, ii):
            yield jj

A = { 'a' : dict(b=1, c=1),
    'c' : dict(d=1),
    'd' : dict(e=1,f=1,g=1),
    'h' : dict(j=1)
    }

for ii in get_all(A,'a'):
    print ii
```
```
Gives me
```
steve@rei:~/code/tmp
$ python recur.py
a
c
d
e
g
f
b
```