替换所有游标行中的值 [英] Replacing value in all cursor rows

问题描述

使用 SQLite 和 Python 3.1，我想通过在 HTML 表中显示货币数据.接受游标作为参数的模板.因此，所有货币值都必须有 2 个小数位，但 SQLite 将它们存储为浮点类型(即使结构声明十进制 :-( )，因此某些必须在显示前进行转换(例如，我希望 12.1 显示为 12.10).

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).

代码是这样的(为了说明而简化)...

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')

最后一条命令抛出错误#builtins.TypeError: 'sqlite3.Row' object does not support item assignment"

The last command throws the error "# builtins.TypeError: 'sqlite3.Row' object does not support item assignment"

如何解决无法更改行对象值的问题?我可以将光标转换为字典列表(每行一个，例如 [{'order_no':1, 'amount':12.1}, {'order_no':2, 'amount':6.32}, ...])，然后格式化每个项目的金额"值?如果是这样，我该怎么做?

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?

是否有更好的解决方案来实现我的目标?任何帮助将不胜感激.

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

TIA，艾伦

推荐答案

是的:

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')

还有其他方法，但这种方法似乎是最简单、最直接的一种.

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

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