Can not auto complete for SQLAlchemy

[archcst]

Other packages can be auto complete(like render_templates):

But SQLAlchemy can't(when I type id = db.Column):

Here's my setup in ~/.spacemacs.d/init.el

(defun dotspacemacs/user-config ()
  ;; python configurations:
  (require 'pyvenv)
  (add-to-list 'company-backends 'company-anaconda)
  (add-to-list 'company-backends 'company-jedi)
  (add-to-list 'company-backends 'company-web)
  (add-hook 'python-mode-hook 'anaconda-mode)
  (add-hook 'python-mode-hook (lambda () (pyvenv-activate (concat (projectile-project-root) "/venv"))))
  (setq web-mode-engines-alist
        '(("django"    . "\\.html\\'")))
  (setq tab-width 4)
  (setq py-indent-offset 4)
  (setq python-spacemacs-indent-guess nil)
  (setq python-indent-guess-indent-offset nil)
  (setq org-confirm-babel-evaluate nil)
)

And here's the pipfile:

Package          Version
---------------- -------
alembic          1.0.11
argh             0.26.2
Click            7.0
Flask            1.1.0
Flask-CKEditor   0.4.3
Flask-Migrate    2.5.2
Flask-SQLAlchemy 2.4.0
Flask-WTF        0.14.2
itsdangerous     1.1.0
jedi             0.14.0
Jinja2           2.10.1
Mako             1.0.13
MarkupSafe       1.1.1
parso            0.5.0
pathtools        0.1.2
pip              19.1.1
python-dateutil  2.8.0
python-dotenv    0.10.3
python-editor    1.0.4
PyYAML           5.1.1
setuptools       39.0.1
six              1.12.0
SQLAlchemy       1.3.5
watchdog         0.9.0
Werkzeug         0.15.4
WTForms          2.2.1

Emacs version:

- OS: darwin
- Emacs: 26.1
- Spacemacs: 0.300.0
- Spacemacs branch: develop (rev. 5df46b200)
- Graphic display: t
- Distribution: spacemacs
- Editing style: vim
- Completion: helm

company-backends:

Value:
((company-anaconda . #1=(:with company-yasnippet))
 (company-semantic company-dabbrev-code company-gtags company-etags company-keywords . #1#)
 (company-files . #1#)
 (company-dabbrev . #1#))
Original value was 
(company-bbdb company-eclim company-semantic company-clang company-xcode company-cmake company-capf company-files
              (company-dabbrev-code company-gtags company-etags company-keywords)
              company-oddmuse company-dabbrev)
Local in buffer app.py; global value is 
(company-web company-jedi company-anaconda company-bbdb company-eclim company-semantic company-clang company-xcode company-cmake company-capf company-files
             (company-dabbrev-code company-gtags company-etags company-keywords)
             company-oddmuse company-dabbrev)