Paging python lists in slices of 4 items
Possible Duplicate:
How do you split a list into evenly sized chunks in Python?
mylist = [1, 2, 3, 4, 5, 6, 7, 8, 9]
I need to pass blocks of these to a third party API that can only deal with 4 items at a time. I could do one at a time but it's a HTTP request and process for each go so I'd prefer to do it in the lowest possible number of queries.
What I'd like to do is chunk the list into blocks of four and submit each sub-block.
So from the above list, I'd expect:
[[1, 2, 3, 4], [5, 6, 7, 8], [9]]
Answer
mylist = [1, 2, 3, 4, 5, 6, 7, 8, 9]
print [mylist[i:i+4] for i in range(0, len(mylist), 4)]
# Prints [[1, 2, 3, 4], [5, 6, 7, 8], [9]]