"""Etching Drawer, by Al Sweigart al@inventwithpython.com An art program that draws a continuous line around the screen using the WASD keys. Inspired by Etch A Sketch toys. For example, you can draw Hilbert Curve fractal with: SDWDDSASDSAAWASSDSASSDWDSDWWAWDDDSASSDWDSDWWAWDWWASAAWDWAWDDSDW Or an even larger Hilbert Curve fractal with: DDSAASSDDWDDSDDWWAAWDDDDSDDWDDDDSAASDDSAAAAWAASSSDDWDDDDSAASDDSAAAAWA ASAAAAWDDWWAASAAWAASSDDSAASSDDWDDDDSAASDDSAAAAWAASSDDSAASSDDWDDSDDWWA AWDDDDDDSAASSDDWDDSDDWWAAWDDWWAASAAAAWDDWAAWDDDDSDDWDDSDDWDDDDSAASDDS AAAAWAASSDDSAASSDDWDDSDDWWAAWDDDDDDSAASSDDWDDSDDWWAAWDDWWAASAAAAWDDWA AWDDDDSDDWWAAWDDWWAASAAWAASSDDSAAAAWAASAAAAWDDWAAWDDDDSDDWWWAASAAAAWD DWAAWDDDDSDDWDDDDSAASSDDWDDSDDWWAAWDD This code is available at https://nostarch.com/big-book-small-python-programming Tags: large, artistic""" import shutil, sys # Set up the constants for line characters: UP_DOWN_CHAR = chr(9474) # Character 9474 is '│' LEFT_RIGHT_CHAR = chr(9472) # Character 9472 is '─' DOWN_RIGHT_CHAR = chr(9484) # Character 9484 is '┌' DOWN_LEFT_CHAR = chr(9488) # Character 9488 is '┐' UP_RIGHT_CHAR = chr(9492) # Character 9492 is '└' UP_LEFT_CHAR = chr(9496) # Character 9496 is '┘' UP_DOWN_RIGHT_CHAR = chr(9500) # Character 9500 is '├' UP_DOWN_LEFT_CHAR = chr(9508) # Character 9508 is '┤' DOWN_LEFT_RIGHT_CHAR = chr(9516) # Character 9516 is '┬' UP_LEFT_RIGHT_CHAR = chr(9524) # Character 9524 is '┴' CROSS_CHAR = chr(9532) # Character 9532 is '┼' # A list of chr() codes is at https://inventwithpython.com/chr # Get the size of the terminal window: CANVAS_WIDTH, CANVAS_HEIGHT = shutil.get_terminal_size() # We can't print to the last column on Windows without it adding a # newline automatically, so reduce the width by one: CANVAS_WIDTH -= 1 # Leave room at the bottom few rows for the command info lines. CANVAS_HEIGHT -= 5 """The keys for canvas will be (x, y) integer tuples for the coordinate, and the value is a set of letters W, A, S, D that tell what kind of line should be drawn.""" canvas = {} cursorX = 0 cursorY = 0 def getCanvasString(canvasData, cx, cy): """Returns a multiline string of the line drawn in canvasData.""" canvasStr = '' """canvasData is a dictionary with (x, y) tuple keys and values that are sets of 'W', 'A', 'S', and/or 'D' strings to show which directions the lines are drawn at each xy point.""" for rowNum in range(CANVAS_HEIGHT): for columnNum in range(CANVAS_WIDTH): if columnNum == cx and rowNum == cy: canvasStr += '#' continue # Add the line character for this point to canvasStr. cell = canvasData.get((columnNum, rowNum)) if cell in (set(['W', 'S']), set(['W']), set(['S'])): canvasStr += UP_DOWN_CHAR elif cell in (set(['A', 'D']), set(['A']), set(['D'])): canvasStr += LEFT_RIGHT_CHAR elif cell == set(['S', 'D']): canvasStr += DOWN_RIGHT_CHAR elif cell == set(['A', 'S']): canvasStr += DOWN_LEFT_CHAR elif cell == set(['W', 'D']): canvasStr += UP_RIGHT_CHAR elif cell == set(['W', 'A']): canvasStr += UP_LEFT_CHAR elif cell == set(['W', 'S', 'D']): canvasStr += UP_DOWN_RIGHT_CHAR elif cell == set(['W', 'S', 'A']): canvasStr += UP_DOWN_LEFT_CHAR elif cell == set(['A', 'S', 'D']): canvasStr += DOWN_LEFT_RIGHT_CHAR elif cell == set(['W', 'A', 'D']): canvasStr += UP_LEFT_RIGHT_CHAR elif cell == set(['W', 'A', 'S', 'D']): canvasStr += CROSS_CHAR elif cell == None: canvasStr += ' ' canvasStr += '\n' # Add a newline at the end of each row. return canvasStr moves = [] while True: # Main program loop. # Draw the lines based on the data in canvas: print(getCanvasString(canvas, cursorX, cursorY)) print('WASD keys to move, H for help, C to clear, ' + 'F to save, or QUIT.') response = input('> ').upper() if response == 'QUIT': print('Thanks for playing!') sys.exit() # Quit the program. elif response == 'H': print('Enter W, A, S, and D characters to move the cursor and') print('draw a line behind it as it moves. For example, ddd') print('draws a line going right and sssdddwwwaaa draws a box.') print() print('You can save your drawing to a text file by entering F.') input('Press Enter to return to the program...') continue elif response == 'C': canvas = {} # Erase the canvas data. moves.append('C') # Record this move. elif response == 'F': # Save the canvas string to a text file: try: print('Enter filename to save to:') filename = input('> ') # Make sure the filename ends with .txt: if not filename.endswith('.txt'): filename += '.txt' with open(filename, 'w', encoding='utf-8') as file: file.write(''.join(moves) + '\n') file.write(getCanvasString(canvas, None, None)) except: print('ERROR: Could not save file.') for command in response: if command not in ('W', 'A', 'S', 'D'): continue # Ignore this letter and continue to the next one. moves.append(command) # Record this move. # The first line we add needs to form a full line: if canvas == {}: if command in ('W', 'S'): # Make the first line a horizontal one: canvas[(cursorX, cursorY)] = set(['W', 'S']) elif command in ('A', 'D'): # Make the first line a vertical one: canvas[(cursorX, cursorY)] = set(['A', 'D']) # Update x and y: if command == 'W' and cursorY > 0: canvas[(cursorX, cursorY)].add(command) cursorY = cursorY - 1 elif command == 'S' and cursorY < CANVAS_HEIGHT - 1: canvas[(cursorX, cursorY)].add(command) cursorY = cursorY + 1 elif command == 'A' and cursorX > 0: canvas[(cursorX, cursorY)].add(command) cursorX = cursorX - 1 elif command == 'D' and cursorX < CANVAS_WIDTH - 1: canvas[(cursorX, cursorY)].add(command) cursorX = cursorX + 1 else: # If the cursor doesn't move because it would have moved off # the edge of the canvas, then don't change the set at # canvas[(cursorX, cursorY)]. continue # If there's no set for (cursorX, cursorY), add an empty set: if (cursorX, cursorY) not in canvas: canvas[(cursorX, cursorY)] = set() # Add the direction string to this xy point's set: if command == 'W': canvas[(cursorX, cursorY)].add('S') elif command == 'S': canvas[(cursorX, cursorY)].add('W') elif command == 'A': canvas[(cursorX, cursorY)].add('D') elif command == 'D': canvas[(cursorX, cursorY)].add('A')