I am using python to extract Arabic tweets from twitter and save it as a CSV file, but when I open the saved file in excel the Arabic language displays as symbols. However, inside python and notepad or word, it looks good. May I know where is the problem?
This is a problem I face frequently with Microsoft Excel when opening CSV files that contain Arabic characters. Try the following workaround that I tested on latest versions of Microsoft Excel on both Windows and MacOS:

Open Excel on a blank workbook
Within the Data tab, click on From Text button (if not
    activated, make  sure an empty cell is selected)
Browse and select the CSV file
In the Text Import Wizard, change the File_origin to "Unicode (UTF-8)"
Go next and from the Delimiters, select the delimiter used in your file e.g. comma
Finish and select where to import the data

The Arabic characters should show correctly.
CSV file with Arabic characters is displayed as symbols in Excel