PTVS lxml code completion does not work

Question

I am trying to use lxml package to parse XML file. Simple code work well in python interpreter. But, PTVS code completion does not show anything about package.
Thus I must find everything by look up API document. It feels like i am using Text Editor not IDE.

from lxml import etree
etree.parse(path)

may I miss something to import package?

Versions:
Windows 10 & VS2017 & Anaconda 4.4.0 & Python 3.6 & lxml 3.8.0

Answer 1

I asked this question to PTVS github and here is answer.

PTVS has an issue with analysing certain libraries.

There are a variety of issues relating to analysis not correctly understanding certain libraries. This issue is to collect those reports and spin them off into properly researched and understood tracker items.