How To Read From A File Using Only Readline()

The code i have right now is this f = open(SINGLE_FILENAME) lines = [i for i in f.readlines()] but my proffessor demands that You may use readline(). You may not use read(), read

Solution 1:

You could use a two-argument iter() version:

lines = iter(f.readline, "")

If you need a list of lines:

lines = list(lines)

Solution 2:

First draft:

lines = []
withopen(SINGLE_FILENAME) as f:
    whileTrue:
        line = f.readline()
        if line:
            lines.append(line)
        else:
            break

I feel fairly certain there is a better way to do it, but that does avoid iterating with for, using read, or using readlines.

You could write a generator function to keep calling readline() until the file was empty, but that doesn't really seem like a large improvement here.