Python turtle.left函数代码示例

def vlocka(velikost=100, pstran=6, rev=False):
    for _ in range(pstran):
        troj(velikost / 3, 3)
        if rev:
            t.left( 360 / pstran )
        else:
            t.right( 360 / pstran )

def polygon(side = 50, angle = None, xstart = None, ystart = None, numberSides = 3, color = 'black', fill = False):
    turtle.pensize(3)
    turtle.speed('fastest')
    turtle.hideturtle()
    if angle != None:
        turtle.left(angle)
    
    turtle.penup()
    if fill == True:
        if xstart != None or ystart != None:
            turtle.goto(xstart, ystart)
        else:
            turtle.goto(0, 0)
        turtle.color(color)
        turtle.pendown()
        turtle.begin_fill()
        turtle.circle(side, 360, numberSides)
        turtle.end_fill()
        turtle.penup()
        
    else:
        turtle.goto(xstart, ystart)
        turtle.color(color)
        turtle.pendown()
        turtle.circle(side, 360, numberSides)
        turtle.penup()
    
    return

def draw(cmds, size=2): #output tree
    stack = []
    for cmd in cmds:
        if cmd=='F':
            turtle.forward(size)
        elif cmd=='-':
            t = random.randrange(0,7,1)
            p = ["Red","Green","Blue","Grey","Yellow","Pink","Brown"]
            turtle.color(p[t])
            turtle.left(15) #slope left
        elif cmd=='+':
            turtle.right(15) #slope right
            t = random.randrange(0,7,1) #рандомная пер. для цвета
            p = ["Red","Green","Blue","Grey","Yellow","Pink","Brown"] #ряд цветов
            turtle.color(p[t]) #выбор цвета из ряда
        elif cmd=='X':
            pass
        elif cmd=='[':
            stack.append((turtle.position(), turtle.heading()))
        elif cmd==']':
            position, heading = stack.pop()
            turtle.penup()
            turtle.setposition(position)
            turtle.setheading(heading)  
            turtle.pendown()
    turtle.update()

def draw_star(size, color):

    turtle.pendown()
    turtle.begin_fill()
    turtle.color(1,1,1)
    turtle.forward(2.5) 
    turtle.left(size)
    turtle.forward(2.5)
    turtle.right(144)
    turtle.forward(2.5)
    turtle.left(size)
    turtle.forward(2.5)
    turtle.right(144)
    turtle.forward(2.5)
    turtle.left(size)
    turtle.forward(2.5)
    turtle.right(144)
    turtle.forward(2.5)
    turtle.left(size)
    turtle.forward(2.5)
    turtle.right(144)
    turtle.forward(2.5)
    turtle.left(size)
    turtle.forward(2.5)
    turtle.right(144)
    turtle.end_fill()
    turtle.penup()

def theStem(stemLength=100):
	turtle.home()
	turtle.forward(25)
	turtle.left(90)
	turtle.pensize(4)
	turtle.color("green")
	turtle.forward(stemLength)

 def draw(self):
     for i in range(0,2):
         turtle.forward(self.length)
         turtle.left(90)
         turtle.forward(self.width)
         turtle.left(90)
     turtle.done()

def at(x, y):
    turtle.penup()
    turtle.home()
    turtle.forward(x)
    turtle.left(90)
    turtle.forward(y)
    turtle.pendown()

def draw_tree(depth, height, branches, leafs, angle):
    """
    Draws the tree using recursion
    :pre: pos(0,0), heading east, up
    :post: pos(0,0), heading east, up
    :param depth: number of layers of sub branches (recursion depth)
    :param height: height of tree
    :param branches: number of branches
    :param leafs: number of leafs
    :param angle: angle between branches
    :return: None
    """
    if depth == 0:
        leafs = random.randint(0, leafs)
        draw_leaf(leafs)
        t.down()
        pass

    else:
        t.color('brown')
        t.forward(height)
        for i in range(1, branches+1):
            t.left(90 - i * angle)
            #random branches
            branches = random.randint(branches-1,branches+5)
            draw_tree(depth - 1, height * HEIGHT_FACTOR, branches, leafs, angle)
            t.right(90 - i * angle)
            #random angle
            angle = random.randint(angle-1, angle+1)
            if depth == 1:
                break
        t.color('brown')
        t.backward(height)

def Minkovskiy(l, n):
	if n == 0:
		turtle.forward(l)
	else:
		for angle in [90, -90, -90, 0, 90, 90, -90, 0]:
			Minkovskiy(l/4, n-1)
			turtle.left(angle)

def drawHouse(wallSize):

    """
    This is the function for drawing house which takes
    wall size as a input.
    :pre: (relative) pos (0,0), heading (east), right
    :post: (relative) pos (wallSize,0), heading (north), up
    :return: total wood required to built the house.
    """
    turtle.down()
    turtle.forward(wallSize)
    turtle.left(90)
    turtle.forward(wallSize)
    maxX = turtle.xcor()
    turtle.left(45)
    turtle.forward(wallSize / math.sqrt(2))
    maxY = turtle.ycor()
    turtle.left(90)
    turtle.forward(wallSize / math.sqrt(2))
    turtle.left(45)
    turtle.forward(wallSize)
    turtle.left(90)
    turtle.forward(wallSize)
    turtle.up()
    return 2 * (wallSize + wallSize / math.sqrt(2))

def robber_move(turtle):
    fifty_fifty = random.randrange(0, 2)
    if fifty_fifty == 0:
        turtle.right(90)
    else:
        turtle.left(90)
    turtle.forward(10)

def drawFins(size):
    
    turtle.fillcolor("red")    
    turtle.setheading(90)
    turtle.begin_fill()
    turtle.forward(0.2*size)
    turtle.left(120)
    turtle.forward(0.6*size) 
    turtle.right(120)
    turtle.forward(0.3*size) 
    turtle.right(40)
    turtle.forward(0.8*size)
    turtle.end_fill()    
    
    turtle.setheading(0)
    
    turtle.begin_fill()

    turtle.penup()
    turtle.forward(size)
    turtle.pendown()
    turtle.begin_fill()
    turtle.right(50)
    turtle.forward(0.8*size) 
    turtle.right(40)
    turtle.forward(0.3*size) 
    turtle.right(120)
    turtle.forward(0.6*size)
    turtle.end_fill()

def drawY(length):
    """
    Draw English character 'Y'
    :pre: (relative) pos (X,Y), heading (east), up
    :post: (relative) pos (X+length,Y), heading (east), up
    :return: None
    """
    turtle.up()
    turtle.left(90)
    turtle.forward(length)
    turtle.right(90)
    turtle.down()
    turtle.right(45)
    turtle.forward(math.sqrt((2 * math.pow((length / 2), 2))))
    # moving at 45 degree angle for length sqrt(((math.pow((length/2)+(math.pow((length/2)),2)))
    # calculated using pythagorean theorem.
    turtle.right(45)
    turtle.forward(length / 2)
    turtle.right(180)
    turtle.forward(length / 2)
    turtle.right(45)
    turtle.forward(math.sqrt((2 * math.pow((length / 2), 2))))
    turtle.right(45)
    turtle.up()
    turtle.right(90)
    turtle.forward(length)
    turtle.left(90)
    turtle.up()

def y_tree(length = 200):
    """
    This function receives a length and draws a tree according to the length
    in an angle 60 between the branches always reducing the next length by
    0.6. The drawing ends when the length is smaller than 10
    :param length: The length of the branch to draw, default 200
    :return: None
    """
    ANGLE_BETWEEN_BRANCHES = 60
    LENGTH_REDUCTION = 0.6
    MIN_LENGTH = 10


    if length <= MIN_LENGTH:
        return
    else:
        turtle.forward(length)                  # draws the branch
        turtle.left(ANGLE_BETWEEN_BRANCHES / 2)
        y_tree(LENGTH_REDUCTION * length)       # draws the left branch

        turtle.right(ANGLE_BETWEEN_BRANCHES)
        y_tree(LENGTH_REDUCTION * length)       # draws the right branch

        turtle.left(ANGLE_BETWEEN_BRANCHES / 2)
        turtle.backward(length)                 # returns back to draw next

def draw_triangle(l):
    i=0
    while(i<3):
        turtle.forward(l)
        turtle.left(120)
        i=i+1
    turtle.done()