$ pip3 install pandas
Requirement already satisfied (use --upgrade to upgrade): pandas in /usr/local/lib/python3.4/dist-packages
Requirement already satisfied (use --upgrade to upgrade): python-dateutil>=2 in /usr/local/lib/python3.4/dist-packages (from pandas)
Requirement already satisfied (use --upgrade to upgrade): pytz>=2011k in /usr/local/lib/python3.4/dist-packages (from pandas)
Requirement already satisfied (use --upgrade to upgrade): numpy>=1.7.0 in /usr/local/lib/python3.4/dist-packages (from pandas)
I am getting Import error while my system has already satisfied all requirements.