map, index

Luis Quesada l.quesada at 4c.ucc.ie
Sun Mar 28 09:26:43 EDT 2010


Dear all,

I am new to Python, so I apologize in advance if you find my questions 
naive (or if they have been already answered in this forum).

1. What is the most pythonic way of mapping a list where the value each 
element is mapped to depends on the index of the element. Is there a way 
of writing the following without using zip:
	map(lambda (id,v):id*v,zip(range(len(L)),L))
I wonder whether there is something like mapInd in Oz 
(http://www.mozart-oz.org/documentation/base/list.html) so that you can 
pass a binary function to map and refer to the index of the element in 
the body of the given function. It would be cool to be able to simply write:
	mapInd(lambda id,v:id*v,L)

2. Is there a higher order index function that lets you specify the 
condition to be met by the returned element. I mean something like:

def my_index(f,L,default):
     for x in L:
         if f(x):return x
     return default

Thanks in advance for your answer!

Cheers,
Luis



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