How to read a large file - line by line?

Question

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

Answer 1

From the python documentation for fileinput.input():

This iterates over the lines of all files listed in sys.argv[1:], defaulting to sys.stdin if the list is empty

further, the definition of the function is:

fileinput.FileInput([files[, inplace[, backup[, mode[, openhook]]]]])

reading between the lines, this tells me that files can be a list so you could have something like:

for each_line in fileinput.input([input_file, input_file]):
  do_something(each_line)

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