I just realized that permutations isn&#39;t quite what you want, as swapping the first &quot;1&quot; for the second &quot;1&quot; gives the same thing.  You can use set to get the unique permutations.<div>e.g.</div><div><div>
In [4]: set(itertools.permutations([1,1,0,0]))</div><div>Out[4]: </div><div>set([(0, 0, 1, 1),</div><div>     (0, 1, 0, 1),</div><div>     (0, 1, 1, 0),</div><div>     (1, 0, 0, 1),</div><div>     (1, 0, 1, 0),</div><div>
     (1, 1, 0, 0)])</div><div><br></div><br><div class="gmail_quote">On Fri, Mar 19, 2010 at 10:17 AM, Joe Kington <span dir="ltr">&lt;<a href="mailto:jkington@wisc.edu">jkington@wisc.edu</a>&gt;</span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="im">See itertools.permutations (python standard library)<div><br></div><div>e.g.</div></div><div><div class="im"><div>In [3]: list(itertools.permutations([1,1,0,0]))</div><div>Out[3]: </div></div><div>[(1, 1, 0, 0),</div>
<div> (1, 1, 0, 0),</div><div> (1, 0, 1, 0),</div>
<div> (1, 0, 0, 1),</div><div> (1, 0, 1, 0),</div><div> (1, 0, 0, 1),</div><div> (1, 1, 0, 0),</div><div> (1, 1, 0, 0),</div><div> (1, 0, 1, 0),</div><div> (1, 0, 0, 1),</div><div class="im"><div> (1, 0, 1, 0),</div><div>
 (1, 0, 0, 1),</div>
<div> (0, 1, 1, 0),</div><div> (0, 1, 0, 1),</div></div><div> (0, 1, 1, 0),</div><div> (0, 1, 0, 1),</div><div> (0, 0, 1, 1),</div><div> (0, 0, 1, 1),</div><div> (0, 1, 1, 0),</div><div> (0, 1, 0, 1),</div><div> (0, 1, 1, 0),</div>

<div> (0, 1, 0, 1),                                                                                                                                                                                                                                     </div>
<div class="im">
<div> (0, 0, 1, 1),</div><div> (0, 0, 1, 1)]</div><div><br></div><div>Hope that helps,</div><div>-Joe</div><br></div><div class="gmail_quote"><div class="im">On Fri, Mar 19, 2010 at 9:53 AM, gerardob <span dir="ltr">&lt;<a href="mailto:gberbeglia@gmail.com" target="_blank">gberbeglia@gmail.com</a>&gt;</span> wrote:<br>

</div><div><div></div><div class="h5"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
Hello, i would like to produce lists of lists 1&#39;s and 0&#39;s.<br>
<br>
For example, to produce the list composed of:<br>
<br>
L = [[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]<br>
<br>
I just need to do the following:<br>
<br>
n=4<br>
numpy.eye(n,dtype=int).tolist()<br>
<br>
I would like to know a simple way to generate a list containing all the<br>
lists having two 1&#39;s at each element.<br>
<br>
Example, n = 4<br>
L2 = [[1,1,0,0],[1,0,1,0],[1,0,0,1],[0,1,1,0],[0,1,0,1],[0,0,1,1]]<br>
<br>
Any ideas?<br>
Thanks.<br>
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