get slice from multi-dimensions in python

Question

LISTA=[["001", "TOM", "13800000001", "AAAA"],["002", "Jerry", "13800000002", "BBBB"]]
name=[]
for ID,NAME,HSNUMBER,ADDRESS in LISTA:
    name.append(NAME)

>>> name
['TOM', 'Jerry']

I feel it is not a simple way to get all the NAME in LISTA,how to revise it ?

score 1 · Answer 1 · answered Mar 18 '14 at 05:58

1

You know that the name will be the second element in the lists, so you can use list comprehension, like this

names = [item[1] for item in LISTA]
print names
# ['TOM', 'Jerry']

answered Mar 18 '14 at 05:58

thefourtheye

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Kei Minagawa · Accepted Answer · 2014-03-18T06:46:17.347

0

I think this is very simple way.

>>> LISTA=[["001", "TOM", "13800000001", "AAAA"],["002", "Jerry", "13800000002", "BBBB"]]
>>> name = zip(*LISTA)[1]
('TOM', 'Jerry')

UPDATE

what is the meaning of * here?

In general

x = func(*[a, b, c])

is equivalent to

x = func(a, b, c)

So here

#zip(*LISTA)
zip(*[["001", "TOM", "13800000001", "AAAA"],["002", "Jerry", "13800000002", "BBBB"]])

is equivalent to

zip(["001", "TOM", "13800000001", "AAAA"],["002", "Jerry", "13800000002", "BBBB"])

edited Mar 18 '14 at 06:46

answered Mar 18 '14 at 06:05

Kei Minagawa

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what is the meaning of `*` here? – showkey Mar 18 '14 at 06:15
It means just passing each element of list as argument. Please see [What does * mean in Python?](http://stackoverflow.com/questions/400739/what-does-mean-in-python) for more detail. – Kei Minagawa Mar 18 '14 at 06:25
in python3 ,it is `list(zip(*LISTA))[1]`. – showkey Mar 18 '14 at 07:58
Ah I didn't know that. In python 2.7 it is `list(itertools.izip(*LISTA))[1]`. – Kei Minagawa Mar 18 '14 at 08:04

get slice from multi-dimensions in python

2 Answers2

UPDATE