def child(self, path):
        l = self.pathList()
        if l[-1] == '':
            l[-1] = path
        else:
            l.append(path)
        return self._pathMod(l, self.queryList(0))
Construct a url where the given path segment is a child of this url
dataset/ETHPy150Open twisted/nevow/nevow/url.py/URL.child