$ 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)
我的系统已满足所有要求时，出现导入错误。