How do I read a random line from one file?

Question

Is there a built-in method to do it? If not how can I do this without costing too much overhead?

Answer 1

You can add the lines into a set() which will change their order randomly.

filename=open("lines.txt",'r')
f=set(filename.readlines())
filename.close()

To find the 1st line:

print(next(iter(f)))

To find the 3rd line:

print(list(f)[2])

To list all the lines in the set:

for line in f:
    print(line)