[Python-Dev] re: Tutorial: Brief Introduction to the Standard Library

Kevin J. Butler python-kbutler at sabaydi.com
Thu Dec 4 16:27:31 EST 2003

From: Arthur <ajsiegel at optonline.net>

>What is fundamentally wrong with copy(list) as an alternative to list[:]?  
Well, copy(list) doesn't contain an emoticon of two beady little eyes 
peeking out of a box, for one.  ;-)

The opposite question, "What is fundamentally wrong with list[:]..." has 
an easy answer:

It takes experience or explanation of slicing to know what it does.  
copy(list) is easy even for novices to understand.

When I know my code will be read by people unfamiliar with Python, I 
tend to annotate use of
slices something like:

    list[:] # copy the list

Python usually makes it easier to avoid sacrificing clarity on the altar 
of micro-optimization, but since the slice is the idiomatically correct 
way to spell copy(list) in Python, that's the way to write it.


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