Importing CSV Files
===================

.. figure:: ../figures/tree_csv.webp
    :width: 397
    :height: 323
    :alt: ttk treeview with imported data
    :align: center
    
    The same Treeview but with imported data
    
    Notice that the strings are quoted

The next task is to make the treeview more generalised, by using csv 
files. This means that our python script is no longer tied to any one 
set of data.

Import the module csv, open and read the csv file, set the
delimiter (data separator) and the first line of the csv file is our 
header data::

    import csv
    ........
    tree_data = []
    csv_file = '../csv/test.csv'
    csv_delimiter = ';'
    ........
    with open(csv_file, newline='', encoding='utf-8-sig') as csvfile:
        treeCsv = csv.reader(csvfile, delimiter=csv_delimiter)
      
        for ix, row in enumerate(treeCsv):
            if ix == 0:
                tree_columns = row
            else:
                tree_data.append(row)

Use a couple of new variables, the name of ``csvfile`` and what delimiter
is being used, by default a comma. Insert these where we had the header and 
data list and tuple. Change tree_data to be an empty list. Construct a csv 
file, strings have to be quoted, and numbers normally have to use decimal 
points (otherwise the delimiter should be a semicolon). If using rgb 
values separated by commas, delimiters become semicolons.

Comment out the column names and data.

After all that you should have the following:-

.. container:: toggle

   .. container:: header

       *Show/Hide Code* 07tree_csv.py

   .. literalinclude:: ../examples/treeview/07tree_csv.py
      :emphasize-lines: 10, 76-78, 81-88

Check that the first row of the csv file corresponds to our column
names, and the succeeding rows are the data, each row ordered as our columns.