Making a terminal-slide-up effect in python

I'm working on a project where i need a transition effect when needed. I'm running this python project through 'cool-retro-term' a CRT terminal emulator.

I want to make it like the old-school CRT terminal's where the screen smoothly slides up all characters to present the next line or to refresh the screen. Like this: Terminal Slide Effect

NOT THE CHARACTERS BEING PRINTED INDIVIDUALLY, BUT THE SCROLLING OF THE SCREEN.

So far the best I've done is create a function with a bunch of empty prints in a loop:

import time

def slide_up():
    for _ in range(30):
        print("")
        time.sleep(0.03)
    clear()

The clear() is a function that clears the terminal screen:

clear = lambda: os.system('clear')

If anyone knows how I could accomplish this effect I'd greatly appreciate it.

Solution

To directly control the screen scrolling, you need something like VT100 control codes. Try this demo. It uses different VT100 control codes to hide/show the cursor and scroll up/down.

import time

def smooth_scroll(lines=10, delay=0.1):
    """
    Smoothly scrolls the terminal up or down a specified number of lines with a delay using VT100 escape codes.

    Args:
    lines (int): The number of lines to scroll. Positive values scroll up, negative values scroll down.
    delay (float): The delay in seconds between each line scroll.
    """
    print("\033[?25l", end="", flush=True)  # Hide the cursor
    
    if lines > 0:
        for _ in range(lines):
            print("\033[1S", end="", flush=True)  # Scroll up one line
            time.sleep(delay)
    else:
        for _ in range(abs(lines)):
            print("\033[1T", end="", flush=True)  # Scroll down one line
            time.sleep(delay)
            
    print("\033[?25h", end="", flush=True)  # Show the cursor

# Example usage
smooth_scroll(lines=20, delay=0.2)  # Scrolls up 20 lines
smooth_scroll(lines=-10, delay=0.2)  # Scrolls down 10 lines

You have to be using a terminal that supports VT100 control codes.