I'm working on a site with a list-type view (shopping cart) where each item has a select drop-down widget to change shipping type. The resulting HTML, created by a for loop such that 'item\_id\_foo' changes on each cycle, looks like:

```
<select name='item_id_foo'>
<option value='bar1'>bar1</option>
...
<input type='submit' name='submit' value='Change'/>
</select>

```

As a result, by request.POST.copy has a key/value like {'item\_id\_foo':'bar1'}. My question is how to find keys that look like 'item\_id\_foo', 'item\_id\_bar', etc. Methods like "getitem", "get" or "contains" assume you know what the full key looks like, and I only know the pattern. How do I match for a pattern on a key?

Thank you,
bkev

Update: Example values for the select would be like:
'item\_id\_1', 'item\_id\_2', 'item\_id\_3'...matching the id of the item in the cart that needs to be edited (each has its own shipping method and fee).