file-read

How to read a large file line by line

泄露秘密 提交于 2019-11-25 21:50:06
问题 I want to iterate over each line of an entire file. One way to do this is by reading the entire file, saving it to a list, then going over the line of interest. This method uses a lot of memory, so I am looking for an alternative. My code so far: for each_line in fileinput.input(input_file): do_something(each_line) for each_line_again in fileinput.input(input_file): do_something(each_line_again) Executing this code gives an error message: device active . Any suggestions? The purpose is to