Differences between readline and readlines in python

Differences between readline and readlines in python

1. readline scenario

F0 = file ("readline.txt", r) while true for line in f0.readline () if not line: breakpass # do something

Readline usage, which is about 3 times faster than fileinput and 3-4 million lines per second. the advantage is that one row of reading does not occupy memory. it is suitable for processing large files, such as files larger than the memory size.

2. readlines scenario

F1 = open ("readline.txt", "r") for line in f1.readlines () # print line

Readlines will read all files into the memory, greatly increasing the speed, but with such a large memory, you can only use readline.