Iterate over Ruby Array in increments of 4 -

i have following array:

csv_array = [1,2,3,4,5,6,7,8,9,10]

i need write each item in array separate csv row, in groups of 4. if this

csv.open("content_file.csv", "wb") |csv|     csv << csv_array end 

i csv file of entire array laid out across 1 row.

i need csv file this:

1,2,3,4

5,6,7,8

9,10

how can write ruby script

csv << csv_array[0..3]
csv << csv_array[4..7]

and on, regardless of how many items in array? using ruby 1.9.3.

csv_array = [1,2,3,4,5,6,7,8,9,10]  csv_array.each_slice(4) |chunk|   p chunk end # >> [1, 2, 3, 4] # >> [5, 6, 7, 8] # >> [9, 10]