extension should start from last dot.(both python and golang)
extension should start from last dot.(both python and golang)

golang:
    ext = filepath.Ext(rel)

    func Ext(path string) string
    Ext returns the file name extension used by path. The extension is
    the suffix beginning at the final dot in the final element of path;
    it is empty if there is no dot.

python:
    In [10]: os.path.splitext?
    Signature: os.path.splitext(p)
    Docstring:
    Split the extension from a pathname.

    Extension is everything from the last dot to the end, ignoring
    leading dots.  Returns "(root, ext)"; ext may be empty.
    File:      /usr/lib/python2.7/posixpath.py
    Type:      function

    In [11]: os.path.splitext('a.b.c.d')
    Out[11]: ('a.b.c', '.d')

elithrar/render,elithrar/render,unrolled/render