Pset7 - Finance: Cannot figure out how to loop through values in list/dict in order to display results in rows in html table

Question

Here is my index route for application.py: https://gist.github.com/837a3f19ac680ccf0ee06cfff647fb86

Here is the outline of my index.html file: https://gist.github.com/acf68454e8cd75ae566bec06781d93a5

I have been working on index everyday for about 2 weeks and I am totally stuck. I have tried multiple different implementations with looping on the backend, loops in my html, loops in both places. I have read the flask documentation, read tutorials on html, python methods, etc. and have gotten nowhere. I can pass one set of values successfully to my index.html page, what I want to do is to loop through holdings, obtain each corresponding value in my code, and then pass them to my index.html table.

Answer 1

What is going to be stored into your holdings value is "A list of dictionaries", where each list item will be one stock.

i.e each list item will correspond to each row of your query: "SELECT stock, shares FROM portfolio WHERE id = :id"

Now iterating over a simple list of fruits ( eg: fruits = ['apples', 'oranges', 'pears', 'apricots'] ) can be done simply as:

for fruit in fruits:

    print "A fruit of type: %s" % fruit

Similarly you can iterate over each holding value as:

for dict in holdings:
    ...TO DO...

Now you have stored the required values in different variables and want to do the same looping in html to print table data. This can be done in the same way in jinja:

syntax for printing a variable name:

{{ variable_name }}

syntax for 'for loop'

{% for item in seq -%}
    {{ item }}
{%- endfor %}

Hence you can do the required task somewhat as:

<tbody>
    {% for dict in holdings %}
        <tr>
            <td>{{ symbol }}</td>
            <td>{{ num_shares }}</td>
                     .
                     .
                     .
        </tr>
    {% endfor %}
</tbody>

ref: http://jinja.pocoo.org/docs/2.9/templates/

Hope this helps. :)

Answer 2

I rewrote my python code as follows:

Query SQL db return stock and shares columns for logged in user, store in variable, rows.

Create an empty list.

If my SQL query is not empty:

For row in rows:

Use lookup function for each stock.

Create dict and store within it, the values for each row in the table(symbol, name, shares, current price, valuation). These are stored in the dict in "key": value pairs.

Use list.append() method to update the stocks list for each pass through row.

My index.html file is where I was having the biggest problem. I rewrote as follows:

Created table headings.

Create table body.

Loop through stocks.

(Here was my mistake, I placed the loop inside my < tr > tags)

< tr >

< td > {{stock.key}} < /td >

...

< /tr >

{ % endfor % }