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<div class="section" id="subgraph">
<h1>subgraph<a class="headerlink" href="#subgraph" title="Permalink to this headline">¶</a></h1>
<dl class="method">
<dt id="networkx.MultiGraph.subgraph">
<tt class="descclassname">MultiGraph.</tt><tt class="descname">subgraph</tt><big>(</big><em>nbunch</em><big>)</big><a class="headerlink" href="#networkx.MultiGraph.subgraph" title="Permalink to this definition">¶</a></dt>
<dd><p>Return the subgraph induced on nodes in nbunch.</p>
<p>The induced subgraph of the graph contains the nodes in nbunch
and the edges between those nodes.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters :</th><td class="field-body"><p class="first"><strong>nbunch</strong> : list, iterable</p>
<blockquote>
<div><p>A container of nodes which will be iterated through once.</p>
</div></blockquote>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns :</th><td class="field-body"><p class="first"><strong>G</strong> : Graph</p>
<blockquote class="last">
<div><p>A subgraph of the graph with the same edge attributes.</p>
</div></blockquote>
</td>
</tr>
</tbody>
</table>
<p class="rubric">Notes</p>
<p>The graph, edge or node attributes just point to the original graph.
So changes to the node or edge structure will not be reflected in
the original graph while changes to the attributes will.</p>
<p>To create a subgraph with its own copy of the edge/node attributes use:
nx.Graph(G.subgraph(nbunch))</p>
<p>If edge attributes are containers, a deep copy can be obtained using:
G.subgraph(nbunch).copy()</p>
<p>For an inplace reduction of a graph to a subgraph you can remove nodes:
G.remove_nodes_from([ n in G if n not in set(nbunch)])</p>
<p class="rubric">Examples</p>
<div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="n">G</span> <span class="o">=</span> <span class="n">nx</span><span class="o">.</span><span class="n">Graph</span><span class="p">()</span> <span class="c"># or DiGraph, MultiGraph, MultiDiGraph, etc</span>
<span class="gp">>>> </span><span class="n">G</span><span class="o">.</span><span class="n">add_path</span><span class="p">([</span><span class="mi">0</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">3</span><span class="p">])</span>
<span class="gp">>>> </span><span class="n">H</span> <span class="o">=</span> <span class="n">G</span><span class="o">.</span><span class="n">subgraph</span><span class="p">([</span><span class="mi">0</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">2</span><span class="p">])</span>
<span class="gp">>>> </span><span class="n">H</span><span class="o">.</span><span class="n">edges</span><span class="p">()</span>
<span class="go">[(0, 1), (1, 2)]</span>
</pre></div>
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