Where is the syntax for the dict() constructor ?!

[Captain Poutine]

I'm simply trying to read a CSV into a dictionary.

(if it matters, it's ZIP codes and time zones, i.e.,
35983,CT
39161,CT
47240,EST



Apparently the way to do this is:

import csv

dictZipZones = {}

reader = csv.reader(open("some.csv", "rb"))
for row in reader:
     # Add the row to the dictionary
	

But how to do this?

Apparently there is no dict.append() nor dict.add()

But what is there?  I see vague references to "the dict() constructor" 
and some examples, and news that it has been recently improved.  But 
where is the full, current documentation for the dict() constructor?

Frustrated,
Captain Poutine