installed pandas but still can't import it
If you're using pycharm you can go to File -> Settings -> Project -> Project Interpreter.
There you'll get a list of all the packages installed with the current python that pycharm is using. There is a '+' sign on the right of the window that you can use to install new packages, just enter pandas there.
I already installed it with pip3 install pandas and using python3.7 but when I try to import pandas and run the code error popping up. 

Traceback (most recent call last):   File
  "/Users/barbie/Python/Test/test.py", line 1, in 
      import pandas as pd ModuleNotFoundError: No module named 'pandas'

and if I try to install again.. it says this. 

pip3 install 
  pandas Requirement already satisfied: pandas in
  /usr/local/lib/python3.7/site-packages (0.23.4) Requirement already
  satisfied: pytz>=2011k in /usr/local/lib/python3.7/site-packages (from
  pandas) (2018.9) Requirement already satisfied: numpy>=1.9.0 in
  /usr/local/lib/python3.7/site-packages (from pandas) (1.15.4)
  Requirement already satisfied: python-dateutil>=2.5.0 in
  /usr/local/lib/python3.7/site-packages (from pandas) (2.7.5)
  Requirement already satisfied: six>=1.5 in
  /usr/local/lib/python3.7/site-packages (from
  python-dateutil>=2.5.0->pandas) (1.12.0)