sympy/sympy — pull request #685 by smichr (2011-10-27 16:03:31+00:00)
Title: change names of imported math functions (e.g. sqrt -> _sqrt)

If 'from math import sqrt' is imported at the main level of a
module, then when someone does 'from module import *' those
functions will wipe out the sympy versions. Places where such
imports occur have been changed so the name is renamed as a
private function, e.g. cos -> _cos.