import os def which(name, flags=os.X_OK): """Analogue of unix 'which'. Borrowed from the Twisted project, see their licence here: https://twistedmatrix.com/trac/browser/trunk/LICENSE Copied from ``pytest_shutil.cmdline.which`` to allow testing on conda-forge where ``pytest-shutil`` is not available. """ result = [] exts = filter(None, os.environ.get('PATHEXT', '').split(os.pathsep)) path = os.environ.get('PATH', None) if path is None: return [] for p in os.environ.get('PATH', '').split(os.pathsep): p = os.path.join(p, name) if os.access(p, flags): result.append(p) for e in exts: pext = p + e if os.access(pext, flags): result.append(pext) return result