how to assign variable values directly from list range

Question

I'm trying to find a better and more pythonic way to this piece of code:

for i in rows:
    row_data = i.findAll('td')
    serial = row_data[0]
    hostname = row_data[1]
    owner = row_data[2]
    memory = row_data[3]
    processor = row_data[4]
    os = row_data[5]
    model = row_data[6]
    ip = row_data[7]

i'm trying to do something like this:

 [serial, hostname, owner, memory, etc..] = row_data[:7]

Any ideas on how this can be achieved?

With or without index i get this message: [serial, hostname, owner, memory, processor, os, model, be_ip] = row_data ValueError: too many values to unpack

score 6 · Accepted Answer · answered Feb 11 '14 at 19:45

6

You can do exactly that:

>>> row_data = ['serial', 'hostname', 'ip']
>>> [serial, hostname, ip] = row_data
>>> serial
'serial'
>>> hostname
'hostname'
>>> ip
'ip'

The square brackets around [serial, hostname, ip] are optional.

answered Feb 11 '14 at 19:45

NPE

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3

Worth mentioning that it's called [unpacking](http://en.wikibooks.org/wiki/Python_Programming/Tuples#Packing_and_Unpacking) – bereal Feb 11 '14 at 19:48
Maybe worth mentioning that `a,b,*tail = (1,2,3,4)` also works fine. – Hyperboreus Feb 11 '14 at 19:54
@Hyperboreus, is that version dependent? (It didn't work and I'm on 2.7.6) – wnnmaw Feb 11 '14 at 19:56
@wnnmaw My bad, seems to be python3 only. – Hyperboreus Feb 11 '14 at 19:58
1

@wnnmaw: Also, see http://stackoverflow.com/questions/5333680/extended-tuple-unpacking-in-python-2 – NPE Feb 11 '14 at 19:58
How come this isn't working for me? [serial, hostname, owner, memory, processor, os, model, be_ip] = row_data ValueError: too many values to unpack – ZeroSoul13 Feb 11 '14 at 20:08
@ZeroSoul13: You have eight variables on the left hand side, and `row_data` contains more than eight values. – NPE Feb 11 '14 at 20:10
Worked. corrected the index [:7] to [:8] and it worked. Thank you for your help. should have seen this one. – ZeroSoul13 Feb 11 '14 at 20:15

how to assign variable values directly from list range

1 Answers1