How can you loop through lines of text and join if the lines are shorter than 50 characters?-CodePudding

I am trying to loop through each line of text in a document and if the line is shorter than 50 characters, then join them together.

What I am having trouble figuring out is the hierarchy of the loop. What I have right now is:

with open(sys.argv[1]) as f1:
    with open(sys.argv[2], 'a') as f2:
        lines = f1.readlines()
        for index, line in enumerate(lines):
            if len(line) > 50:
                f2.write(line)
            else:
                # Something that would take the next line and join to the current index
                line1 = line

I need to keep the current line and then loop again for the next line to join. Could I use a while loop and add the line from the next index?

CodePudding user response：

This would concatenate lines until it sees a line with more than 50 characters.

with open(sys.argv[1]) as f1:
    with open(sys.argv[2], 'a') as f2:
        lines = f1.readlines()
        prev_line = ""
        for index, line in enumerate(lines):
            if len(line) > 50:
                f2.write(prev_line   line)
                prev_line = ""
            else:
                prev_line  = line

If you need to write once the concatenated line reaches 50 characters:

with open(sys.argv[1]) as f1:
    with open(sys.argv[2], 'a') as f2:
        lines = f1.readlines()
        prev_line = ""
        for index, line in enumerate(lines):
            line  = prev_line
            if len(line) > 50:
                f2.write(line)
                prev_line = ""
            else:
                prev_line  = line