Question

I have searched for the problem I am having, but have seen different variations of it that don’t help me much (I am fairly new to Python; taking it as part of an introduction to programming at a university).

The Problem: I keep getting a TypeError talking about the number of arguments, but I (with my so far limited knowledge of Python) do not see what is wrong.

I have the following functions:

def Grid():
borderSet = 20
spaceSize = 50
totalSpaces = 10

boardX = borderSet + (totalSpaces * spaceSize) + (10 * borderSet)
boardY = borderSet + (totalSpaces * spaceSize) + borderSet

board = GraphWin("Hunt the Wumpus", boardX, boardY)

for r in range(totalSpaces):
    for c in range(totalSpaces):
        gridTile = Rectangle(Point(borderSet+ r*spaceSize, borderSet+c*spaceSize), Point(borderSet+(r+1)*spaceSize, borderSet+(c+1)*spaceSize))
        gridTile.setWidth(2)
        gridTile.draw(board)
        gridTileText = Text(Point(((gridTile.getP1().getX() + gridTile.getP2().getX()) / 2), ((gridTile.getP1().getY() + gridTile.getP2().getY()) / 2)), False)
        gridTileText.draw(board)

ctr = DrawCharacter(borderSet, spaceSize)
ctr.draw(board)

a, w, p, t = ChooseDifficulty(boardX, boardY)

Text(Point(boardX - (6 * borderSet), 15 * borderSet), ("Number of arrows:", a)).draw(board)
Text(Point(boardX - (6 * borderSet), 16 * borderSet), ("Number of wumpii:", w)).draw(board)
Text(Point(boardX - (6 * borderSet), 17 * borderSet), ("Number of pits:", p)).draw(board)
Text(Point(boardX - (6 * borderSet), 18 * borderSet), ("Number of treasures:", t)).draw(board)

gW, gWT, gE, gET = Controls(boardX, boardY, borderSet)
gW.draw(board)
gWT.draw(board)
gE.draw(board)
gET.draw(board)
#gN.draw(board)
#gNT.draw(board)
#gS.draw(board)
#gST.draw(board)

click = board.getMouse()

#moveN = rectIntersect(gN, click)
#moveS = rectIntersect(gS, click)
moveE = rectIntersect(gE, click)
moveW = rectIntersect(gW, click)

board.getMouse()

Text(Point(boardX / 2, boardY / 2), (moveE, moveW)).draw(board)

board.getMouse()

ch = MoveCharacter(ctr, moveE, moveW)
ch.draw(board)

board.getMouse()
board.close()

return boardX, boardY

and

def Controls(bX, bY, bS):
    wP = [Point(bX - (10 * bS) + 5, bS + 80), Point(bX - (10 * bS) + 105, bS + 120)]
    eP = [Point(bX - (10 * bS) + 120, bS + 80), Point(bX - (10 * bS) + 220, bS + 120)]

    goWest = Rectangle(wP)
    goWestText = Text(Point(bX - (10 * bS) + 55, bS + 100), "Turn Left")
    goWestText.setStyle("bold")
    goWest.setFill(color_rgb(190, 30, 10))
    goWestText.setFill(color_rgb(255, 255, 255))

    goEast = Rectangle(eP)
    goEastText = Text(Point(bX - (10 * bS) + 145, bS + 100), "Turn Right")
    goEastText.setStyle("bold")
    goEast.setFill(color_rgb(10, 190, 30))

    return goWest, goWestText, goEast, goEastText

and I get the following error:

Traceback (most recent call last):
  File "<pyshell#15>", line 1, in <module>
    Grid()
  File "<pyshell#5>", line 29, in Grid
    gW, gWT, gE, gET = Controls(boardX, boardY, borderSet)
  File "<pyshell#11>", line 10, in Controls
    goWest = Rectangle(wP)
TypeError: __init__() takes exactly 3 arguments (2 given)

Answer 1

It’s hard to tell because you’ve provided so much code, but I believe what’s going on is this:

wP = [Point(bX - (10 * bS) + 5, bS + 80), Point(bX - (10 * bS) + 105, bS + 120)]

This makes wP a list of two elements. Even though it contains two things, it’s still a single object.

goWest = Rectangle(wP)

I’m guessing that the Rectangle constructor is supposed to be passed two points as arguments. Along with the implicit self parameter that always refers to the object itself, that makes a total of 3 arguments. Python is complaining that it’s only seeing two parameters passed, namely the implicit self and your list wP.

If this is in fact the problem, one way to fix this would be

goWest = Rectangle(wP[0], wP[1])

A slightly more advanced way would be

goWest = Rectangle(*wP)

The * (argument unpacking) operator basically automates the process of expanding the list elements into individual arguments. f(*args) is equivalent to

f(args[0], args[1], args[2], ...)