def FixVCMacroSlashes(s):
  if '$' in s:
    s = fix_vc_macro_slashes_regex.sub(r'\1', s)
  return s
s1 - s2 -> remove keys in s2 from s1.
dataset/ETHPy150Open adobe/brackets-shell/gyp/pylib/gyp/MSVSSettings.py/FixVCMacroSlashes--crossover with--dataset/ETHPy150Open ipython/ipython-py3k/IPython/utils/ipstruct.py/Struct.__sub__