sympy/sympy — pull request #2595 by lidavidm (2013-11-14 03:01:46+00:00)
Title: Recognize integers when splitting symbols for implicit parsing

Fixes Github issue #2589. Note that a string like `x123.5y` will lead to unexpected results because of how the tokenizer works (it'll give a name `x123`, a number `.5`, and a name `y`).