# Graph method to get subgraph (including descendants) given a set of vertex IDs

**URL:** <https://igraph.discourse.group/t/graph-method-to-get-subgraph-including-descendants-given-a-set-of-vertex-ids/1926>\
**Category:** Usage\
**Tags:** Python\
**Created:** [24 January 2025 00:26 UTC](https://igraph.discourse.group/t/graph-method-to-get-subgraph-including-descendants-given-a-set-of-vertex-ids/1926 "2025-01-24T00:26:33Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![nparham](https://yyz2.discourse-cdn.com/free1/user_avatar/igraph.discourse.group/nparham/32/864_2.png) [@nparham](https://igraph.discourse.group/u/nparham)\
**Post date:** [24 January 2025 00:26 UTC](https://igraph.discourse.group/t/graph-method-to-get-subgraph-including-descendants-given-a-set-of-vertex-ids/1926/1 "2025-01-24T00:26:33Z")

</div>

Would it be possible to extend induced\_subgraph(vids) to include an argument such as mode/method where you can opt to include all descendants or all ancestors along with vids. Or is there an elegant way to implement this with current available methods?

---

<div class="post-metadata">

**Author:** ![nparham](https://yyz2.discourse-cdn.com/free1/user_avatar/igraph.discourse.group/nparham/32/864_2.png) [@nparham](https://igraph.discourse.group/u/nparham)\
**Post date:** [24 January 2025 00:53 UTC](https://igraph.discourse.group/t/graph-method-to-get-subgraph-including-descendants-given-a-set-of-vertex-ids/1926/2 "2025-01-24T00:53:59Z")

</div>

Or perhaps the better candidate is bfs() but allowing vid to be a singular ID or list of IDs.

---

<div class="post-metadata">

**Author:** ![vtraag](https://yyz2.discourse-cdn.com/free1/user_avatar/igraph.discourse.group/vtraag/32/38_2.png) [@vtraag](https://igraph.discourse.group/u/vtraag)\
**Post date:** [24 January 2025 07:39 UTC](https://igraph.discourse.group/t/graph-method-to-get-subgraph-including-descendants-given-a-set-of-vertex-ids/1926/3 "2025-01-24T07:39:32Z")

</div>

You might want to check out [`subcomponent`](https://python.igraph.org/en/main/api/igraph.GraphBase.html#subcomponent), I think that does (mostly) what you would want.