Getting the amount of available lines in a terminal

Determining by that screen shot, you are on Windows

This is from http://code.activestate.com/recipes/440694-determine-size-of-console-window-on-windows/

from ctypes import windll, create_string_buffer

# stdin handle is -10
# stdout handle is -11
# stderr handle is -12

h = windll.kernel32.GetStdHandle(-12)
csbi = create_string_buffer(22)
res = windll.kernel32.GetConsoleScreenBufferInfo(h, csbi)

if res:
    import struct
    (bufx, bufy, curx, cury, wattr,
     left, top, right, bottom, maxx, maxy) = struct.unpack("hhhhHhhhhhh", csbi.raw)
    sizex = right - left + 1
    sizey = bottom - top + 1
else:
    sizex, sizey = 80, 25 # can't determine actual size - return default values

print sizex, sizey, curx, cury

That will give you screen size, and the cursor position.

cury is the line, so you can calculate the number of lines left.

However, you may want to re-check the console window size as you progress, as the user may resize the window at any time.