tags:

views:

66

answers:

4

How can I append the content of each of the following tuples (ie, elements within the list) to another list which already has 'something' in it? So, I want to append the following to a list (eg: result[]) which isn't empty:

l = [('AAAA', 1.11), ('BBB', 2.22), ('CCCC', 3.33)]

Obviously, the following doesn't do the thing:

for item in l:
    result.append(item)
    print result

I want to printout:

[something, 'AAAA', 1.11] 
[something, 'BBB', 2.22] 
[something, 'CCCC', 3.33]

Please help. Many thanks in advance.

+8  A: 
result.extend(item)
Ignacio Vazquez-Abrams
+1. This is the cleanest version.
Skurmedel
Nifty, didn't know `extend` would just handle the tuple the right way.
John
+1 I second the "cleanest".
Kit
@John: `list.extend()` takes any iterable.
Ignacio Vazquez-Abrams
+1 Not only clean, but also very efficient.
zdav
+1  A: 

You can use the inbuilt list() function to convert a tuple to a list. So an easier version is:

l = [('AAAA', 1.11), ('BBB', 2.22), ('CCCC', 3.33)]
result = [list(t) for t in l]
print result

Output:

[['AAAA', 1.1100000000000001],
 ['BBB', 2.2200000000000002],
 ['CCCC', 3.3300000000000001]]
cletus
why do I get: TypeError: 'tuple' object is not callable?
DGT
@DGT no idea. what version of python are you using? The above is fine in 2.6/2.7.
cletus
@DGT: You're probably omitting a comma following a tuple. Something like (a, b, c) (d, e, f) will produce that error. The fixed version would be (a, b, c), (d, e, f)
Dan Breslau
A: 

You will need to unpack the tuple to append its individual elements. Like this:

l = [('AAAA', 1.11), ('BBB', 2.22), ('CCCC', 3.33)]

for each_tuple in l:
  result = ['something']
  for each_item in each_tuple:
    result.append(each_item)
    print result

You will get this:

['something', 'AAAA', 1.1100000000000001]
['something', 'BBB', 2.2200000000000002]
['something', 'CCCC', 3.3300000000000001]

You will need to do some processing on the numerical values so that they display correctly, but that would be another question.

Kit
No​, not this​.
Ignacio Vazquez-Abrams
+4  A: 

You can convert a tuple to a list easily:

>>> t = ('AAA', 1.11)
>>> list(t)
['AAAA', 1.11]

And then you can concatenate lists with extend:

>>> t = ('AAA', 1.11)
>>> result = ['something']
>>> result.extend(list(t))
['something', 'AAA', 1.11])
John
+1 I didn't know about `extend()` :)
Kit