Question

How can I extract elements in a list of lists and create another one in python. So, I want to get from this:

all_list = [['1 2 3 4','2 3 4 5'],['2 4 4 5', '3 4 5 5' ]]

a new list like this:

list_of_lists = [[('3','4'),('4','5')], [('4','5'),('5','5')]]

Following is what I did, and it doesn’t work.

for i in xrange(len(all_lists)):
   newlist=[]
   for l in all_lists[i]:
      mylist = l.split()
      score1 = float(mylist[2])
      score2 = mylist[3]
      temp_list = (score1, score2)
      newlist.append(temp_list)
   list_of_lists.append(newlist)

Please help. Many thanks in advance.

Answer 1

It could work almost as-is if you filled in the value for mylist — right now its undefined.

Hint: use the split function on the strings to break them up into their components, and you can fill mylist with the result.

Hint 2: Make sure that newlist is set back to an empty list at some point.