Python how to read N number of lines at a time

Question

I am writing a code to take an enormous textfile (several GB) N lines at a time, process that batch, and move onto the next N lines until I have completed the entire file.

Answer 1

Assuming "batch" means to want to process all 16 recs at one time instead of individually, read the file one record at a time and update a counter; when the counter hits 16, process that group.

interim_list = []
infile = open("my_very_large_text_file", "r")
ctr = 0
for rec in infile:
    interim_list.append(rec)
    ctr += 1
    if ctr > 15:
        process_list(interim_list)
        interim_list = []
        ctr = 0


the final group

process_list(interim_list)