def computed_displaywidth():
try:<EOL><INDENT>width = int(os.environ['<STR_LIT>'])<EOL><DEDENT>except (KeyError, ValueError):<EOL><INDENT>width = get_terminal_size().columns<EOL><DEDENT>return width or <NUM_LIT><EOL>
Figure out a reasonable default with. Use os.environ['COLUMNS'] if possible,
    and failing that use 80.