How to read a 10GB (or larger) file size in python?

If you had to open large files, you could operate on chunks, and not one byte at a time. To be precocious, make sure RAM of the target machine is enough How are you operating on the file? What are you returning from the file? In what pattern are you accessing the date on the file (like maybe in random sampling or using some serialized mechanism)? There could be many factors that could affect your response to this question.