Python是一种解释型、面向对象、动态数据类型的高级程序设计语言。自从20世纪90年代初Python语言诞生至今，它逐渐被广泛应用于处理系统管理任务和Web编程。Python已经成为最受欢迎的程序设计语言之一。
tkinter模块(“Tk 接口”)是Python的标准Tk GUI工具包的接口，Tk和Tkinter可以在大多数的Unix平台下使用，同样可以应用在Windows和Mac系统里，Tk8.0的后续版本可以实现本地窗口风格，并良好地运行在绝大多数平台中。
由于Tkinter是内置到Python的安装包中，只要安装好Python之后就能import Tkinter库、而且IDLE也是用Tkinter编写而成，对于简单的图形界面Tkinter还是能应付自如。
下面我们来看看如何使用Python中的tkinter模块画一棵漂亮的树。
代码可以到Linux公社资源站下载：
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具体下载目录在 /2020年资料/4月/13日/使用Python中的tkinter模块画树/
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效果图如下：
代码：
# -*- coding: utf-8 -*- import Tkinter import sys, random, math class Point(object): def __init__(self, x, y): self.x = x self.y = y def __str__(self): return "<Point>: (%f, %f)" % (self.x, self.y) class Branch(object): def __init__(self, bottom, top, branches, level = 0): self.bottom = bottom self.top = top self.level = level self.branches = branches self.children = [] def __str__(self): s = "Top: %s, Bottom: %s, Children Count: %d" % \ (self.top, self.bottom, len(self.children)) return s def nextGen(self, n = -1, rnd = 1): if n <= 0: n = self.branches if rnd == 1: n = random.randint(n / 2, n * 2) if n <= 0: n = 1 dx = self.top.x - self.bottom.x dy = self.top.y - self.bottom.y r = 0.20 + random.random() * 0.2 if self.top.x == self.bottom.x: # 如果是一条竖线 x = self.top.x y = dy * r + self.bottom.y elif self.top.y == self.bottom.y: # 如果是一条横线 x = dx * r + self.bottom.x y = self.top.y else: x = dx * r y = x * dy / dx x += self.bottom.x y += self.bottom.y oldTop = self.top self.top = Point(x, y) a = math.pi / (2 * n) for i in range(n): a2 = -a * (n - 1) / 2 + a * i - math.pi a2 *= 0.9 + random.random() * 0.2 self.children.append(self.mkNewBranch(self.top, oldTop, a2)) def mkNewBranch(self, bottom, top, a): dx1 = top.x - bottom.x dy1 = top.y - bottom.y r = 0.9 + random.random() * 0.2 c = math.sqrt(dx1 ** 2 + dy1 ** 2) * r if dx1 == 0: a2 = math.pi / 2 else: a2 = math.atan(dy1 / dx1) if (a2 < 0 and bottom.y > top.y) \ or (a2 > 0 and bottom.y < top.y) \ : a2 += math.pi b = a2 - a dx2 = c * math.cos(b) dy2 = c * math.sin(b) newTop = Point(dx2 + bottom.x, dy2 + bottom.y) return Branch(bottom, newTop, self.branches, self.level + 1) class Tree(object): def __init__(self, root, canvas, bottom, top, branches = 3, depth = 3): self.root = root self.canvas = canvas self.bottom = bottom self.top = top self.branches = branches self.depth = depth self.new() def gen(self, n = 1): for i in range(n): self.getLeaves() for node in self.leaves: node.nextGen() self.show() def new(self): self.leavesCount = 0 self.branch = Branch(self.bottom, self.top, self.branches) self.gen(self.depth) print "leaves count: %d" % self.leavesCount def chgDepth(self, d): self.depth += d if self.depth < 0: self.depth = 0 if self.depth > 10: self.depth = 10 self.new() def chgBranch(self, d): self.branches += d if self.branches < 1: self.branches = 1 if self.branches > 10: self.branches = 10 self.new() def getLeaves(self): self.leaves = [] self.map(self.findLeaf) def findLeaf(self, node): if len(node.children) == 0: self.leaves.append(node) def show(self): for i in self.canvas.find_all(): self.canvas.delete(i) self.map(self.drawNode) self.canvas.tag_raise("leaf") def exit(self, evt): sys.exit(0) def map(self, func = lambda node: node): # 遍历树 children = [self.branch] while len(children) != 0: newChildren = [] for node in children: func(node) newChildren.extend(node.children) children = newChildren def drawNode(self, node): self.line2( # self.canvas.create_line( node.bottom.x, node.bottom.y, node.top.x, node.top.y, fill = "#100", width = 1.5 ** (self.depth - node.level), tags = "branch level_%d" % node.level, ) if len(node.children) == 0: # 画叶子 self.leavesCount += 1 self.canvas.create_oval( node.top.x - 3, node.top.y - 3, node.top.x + 3, node.top.y + 3, fill = "#090", tag = "leaf", ) self.canvas.update() def line2(self, x0, y0, x1, y1, width = 1, fill = "#000", minDist = 10, tags = ""): dots = midDots(x0, y0, x1, y1, minDist) dots2 = [] for i in range(len(dots) - 1): dots2.extend([dots[i].x, dots[i].y, dots[i + 1].x, dots[i + 1].y]) self.canvas.create_line( dots2, fill = fill, width = width, smooth = True, tags = tags, ) def midDots(x0, y0, x1, y1, d): dots = [] dx, dy, r = x1 - x0, y1 - y0, 0 if dx != 0: r = float(dy) / dx c = math.sqrt(dx ** 2 + dy ** 2) n = int(c / d) + 1 for i in range(n): if dx != 0: x = dx * i / n y = x * r else: x = dx y = dy * i / n if i > 0: x += d * (0.5 - random.random()) * 0.25 y += d * (0.5 - random.random()) * 0.25 x += x0 y += y0 dots.append(Point(x, y)) dots.append(Point(x1, y1)) return dots if __name__ == "__main__": root = Tkinter.Tk() root.title("Tree") gw, gh = 800, 600 canvas = Tkinter.Canvas(root, width = gw, height = gh, ) canvas.pack() tree = Tree(root, canvas, Point(gw / 2, gh - 20), Point(gw / 2, gh * 0.2), \ branches = 2, depth = 8) root.bind("n", lambda evt: tree.new()) root.bind("=", lambda evt: tree.chgDepth(1)) root.bind("+", lambda evt: tree.chgDepth(1)) root.bind("-", lambda evt: tree.chgDepth(-1)) root.bind("b", lambda evt: tree.chgBranch(1)) root.bind("c", lambda evt: tree.chgBranch(-1)) root.bind("q", tree.exit) root.mainloop()