sequences

I assumed sequence types in Python were value types. It turns out they're reference types (Meaning that the value of a variable won't be copied when assigned to a new variable, but referenced). So now I'm wondering, what are the value types in Python? That is, what types in Python can I assign to new variables without worrying that the variable was referenced? All values in Python are references. What you need to worry about is if a type is mutable . The basic numeric and string types, as well as tuple and frozenset are immutable; names that are bound to an object of one of those types can

I want to write a function that accepts a parameter which can be either a sequence or a single value. The type of value is str, int, etc., but I don't want it to be restricted to a hardcoded list. In other words, I want to know if the parameter X is a sequence or something I have to convert to a sequence to avoid special-casing later. I could do type(X) in (list, tuple) but there may be other sequence types I'm not aware of, and no common base class. -N. Edit : See my "answer" below for why most of these answers don't help me. Maybe you have something better to suggest. The problem with all of

What are the other ways of achieving auto-increment in oracle other than use of triggers? As far as I can recall from my Oracle days, you can't achieve Auto Increment columns without using TRIGGER. Any solutions out there to make auto increment column involves TRIGGER and SEQUENCE (I'm assuming you already know this, hence the no trigger remarks). You can create and use oracle sequences. The syntax and details are at http://www.techonthenet.com/oracle/sequences.php Also read the article http://rnyb2.blogspot.com/2006/02/potential-pitfall-with-oracle-sequence.html to understand the limitations

Does anyone have a good way of implementing something like a sequence in SQL server? Sometimes you just don't want to use a GUID, besides the fact that they are ugly as heck. Maybe the sequence you want isn't numeric? Besides, inserting a row and then asking the DB what the number is just seems so hackish. sqljunkieshare Sql Server 2012 has introduced SEQUENCE objects , which allow you to generate sequential numeric values not associated with any table. Creating them are easy: CREATE SEQUENCE Schema.SequenceName AS int INCREMENT BY 1 ; An example of using them before insertion: DECLARE @NextID

MySQL provides an automatic mechanism to increment record IDs. This is OK for many purposes, but I need to be able to use sequences as offered by ORACLE. Obviously, there is no point in creating a table for that purpose. The solution SHOULD be simple: 1) Create a table to hosts all the needed sequences, 2) Create a function that increases the value of a specific sequence and returns the new value, 3) Create a function that returns the current value of a sequence. In theory, it looks simple... BUT... When increasing the value of a sequence (much the same as nextval in Oracle), you need to

This question already has an answer here: How to make a flat list out of list of lists 42 answers If I have sequence of sequences (maybe a list of tuples) I can use itertools.chain() to flatten it. But sometimes I feel like I would rather write it as a comprehension. I just can't figure out how to do it. Here's a very construed case: Let's say I want to swap the elements of every pair in a sequence. I use a string as a sequence here: >>> from itertools import chain >>> seq = '012345' >>> swapped_pairs = zip(seq[1::2], seq[::2]) >>> swapped_pairs [('1', '0'), ('3', '2'), ('5', '4')] >>> "".join