Fix missing str to int conversion in the commit f71ddd42 (#25861)
Summary:
Came up in internal testing w/ python 2.7
Pull Request resolved: https://github.com/pytorch/pytorch/pull/25861
Differential Revision: D17261070
Pulled By: soumith
fbshipit-source-id: 412fe5e53ef4d8f2564d77dd17b480bb58cc391e
