Say I have a list of strings like so:
list = ["Jan 1", "John Smith", "Jan 2", "Bobby Johnson"]
How can I split them into two separate lists like this? My teacher mentioned something about indexing but didn't do a very good job of explaining it
li1 = ["Jan 1", "John Smith"]
li2 = ["Jan 2", "Bobby Johnson"]
Well, use list slicing:
li1 = my_list[:2]
li2 = my_list[2:]
BTW, don't use the name list for a variable because you are shadowing the built-in list type.
If your list is longer than just two entries you could do this:
zip(list[0::2],list[1::2])
Output:
[('Jan 1', 'John Smith'), ('Jan 2', 'Bobby Johnson')]
One of ways to do make it work with lists of arbitrary length in a clean and simple manner:
all_lists = (list[x:x+2] for x in range(0, len(list), 2))
And then you can access new lists by:
li1 = all_lists[0]
li2 = all_lists[1]
Or just iterate through them:
for new_list in all_lists:
print(new_list)
As all_lists is a generator (in both Python 2.X and 3.X) it will also work on large chunks of data.
If the length of the list isn't always going to be the same, or known from the start you can do this:
original_list = [YOUR ORIGINAL LIST]
A = [:len(original_list)/2]
B = [len(original_list)/2:]
A will be the first half and B will be the second half.
