update pgadmin 4 ubuntu code example

Example: install pgadmin4 in ubuntu

sudo apt-get update
sudo apt-get install build-essential libssl-dev libffi-dev libgmp3-dev virtualenv python-pip libpq-dev python-dev
mkdir pgAdmin4
cd pgAdmin4
virtualenv pgAdmin4
cd pgAdmin4
source bin/activate
wget https://ftp.postgresql.org/pub/pgadmin/pgadmin4/v2.1/pip/pgadmin4-2.1-py2.py3-none-any.whl
pip install pgadmin4-2.1-py2.py3-none-any.whl
nano lib/python2.7/site-packages/pgadmin4/config_local.py
import os
DATA_DIR = os.path.realpath(os.path.expanduser(u'~/.pgadmin/'))
LOG_FILE = os.path.join(DATA_DIR, 'pgadmin4.log')
SQLITE_PATH = os.path.join(DATA_DIR, 'pgadmin4.db')
SESSION_DB_PATH = os.path.join(DATA_DIR, 'sessions')
STORAGE_DIR = os.path.join(DATA_DIR, 'storage')
SERVER_MODE = False
python lib/python2.7/site-packages/pgadmin4/pgAdmin4.py
pip install flask-htmlmin
python lib/python2.7/site-packages/pgadmin4/pgAdmin4.py
http://localhost:5050