Question

Using SQLite and Python 3.1, I want to display currency data in a HTML table via. a template which accepts a cursor as a parameter. Hence all currency values must have 2 decimal places, but SQLite stores them as float type (even though the structure states decimal 🙁 ) so some must be converted before display (eg. I want 12.1 displayed as 12.10).

The code goes something like this (simplified for illustration)…

import sqlite3
con = sqlite3.connect("mydb")
con.row_factory = sqlite3.Row

cur = con.cursor()
cur.execute("select order_no, amount from orders where cust_id=123")

for row in cur:
   row['amount'] = format(row['amount'],'%.2f')

The last command throws the error “# builtins.TypeError: ‘sqlite3.Row’ object does not support item assignment”

How can I solve the problem whereby the row object values cannot be changed? Could I convert the cursor to a list of dictionaries (one for each row, eg. [{‘order_no’:1, ‘amount’:12.1}, {‘order_no’:2, ‘amount’:6.32}, …]), then format the ‘amount’ value for each item? If so, how can I do this?

Are there any better solutions for achieving my goal? Any help would be appreciated.

TIA,
Alan

Answer 1

Yep:

cur.execute("select order_no, amount from orders where cust_id=123")
dictrows = [dict(row) for row in cur]
for r in dictrows:
  r['amount'] = format(r['amount'],'%.2f')

There are other ways, but this one seems the simplest and most direct one.