how to get the ordinal number in list

[Roy Smith]

In article <338e8fb0-c9ec-462a-b560-1c1ff77de17e at googlegroups.com>,
 Rustom Mody <rustompmody at gmail.com> wrote:

> [To the OP]
> Yeah I am in the minority at least out here in considering
> comprehensions simpler than loops. Take your pick

When comprehensions first came out, I stubbornly refused to get my head 
around them.  Now, I'm totally addicted.  To the extent that I consider 
dict comprehensions to the THE killer feature of 2.7 :-)

But, putting on my instructor's hat, I think it's important to answer 
questions at a level that can be understood by the student.  Painting 
with a broad brush, there's three or four kinds of people asking 
questions on this list:

1) People who are totally new to programming, and are learning Python as 
their first language.  These are the people who are still struggling to 
understand fundamental concepts.  They haven't figured out yet that the 
first step to solving a problem is to decide what algorithms you're 
going to use, and only then can you start translating that into code.  
They need to be led in small steps towards basic knowledge.

2) People who are (at least somewhat) experienced programmers, and are 
learning Python as a second language.  Their experiential background is 
limited to one way of doing things (i.e. the Java way, or the PHP way, 
or whatever language way they learned first).  They mostly should be 
shown how translate the things they already know into familiar feeling 
constructs.  You already know how to write a loop, this is how we do it 
in Python.  You already know how build a data structure that maps keys 
to values, this is how we do it in Python.  Only after they've become 
comfortable with that, should they start exploring the really cool 
features of Python.

3) People who already know many languages, and are learning Python as 
their n-th.  These folks have seen multiple ways of doing things, and 
can understand concepts at a higher level.  Oh, Python dicts are more 
like C++ STL maps than PHP arrays.  Oh, variables have function scope 
and don't have to be explicitly declared.  Oh, RAII is spelled "with" in 
this language.  Oh, functions are first-class objects, but code blocks 
are not.

4) People who are already proficient Python programmers and are looking 
to explore deeper topics.

I think suggesting comprehensions in an answer should be reserved for 
people at levels 3 and 4.  Maybe level 2-1/2.  Certainly not level 1.