python字典操作实例详解

#!/usr/bin/env python3# -*- coding: utf-8 -*-import turtle ##全局变量###词频排列显示个数count = 10#单词频率数组-作为y轴数据data = []#单词数组-作为x轴数据words = []#y轴显示放大倍数-可以根据词频数量进行调节yScale = 6#x轴显示放大倍数-可以根据count数量进行调节xScale = 30 ################# Turtle Start #################### #从点(x1,y1)到(x2,y2)绘制线段def drawLine(t, x1, y1, x2, y2):  t.penup()  t.goto (x1, y1)  t.pendown()  t.goto (x2, y2) # 在坐标(x,y)处写文字def drawText(t, x, y, text):  t.penup()  t.goto (x, y)  t.pendown()  t.write(text) def drawGraph(t):  #绘制x/y轴线  drawLine (t, 0, 0, 360, 0)  drawLine (t, 0, 300, 0, 0)   #x轴: 坐标及描述  for x in range(count):    x=x+1 #向右移一位,为了不画在原点上    drawText(t, x*xScale-4, -20, (words[x-1]))    drawText(t, x*xScale-4, data[x-1]*yScale+10, data[x-1])  drawBar(t) #绘制一个柱体def drawRectangle(t, x, y):  x = x*xScale  y = y*yScale#放大倍数显示  drawLine(t, x-5, 0, x-5, y)  drawLine(t, x-5, y, x+5, y)  drawLine(t, x+5, y, x+5, 0)  drawLine(t, x+5, 0, x-5, 0)   #绘制多个柱体def drawBar(t):  for i in range(count):    drawRectangle(t, i+1, data[i])  ################# Turtle End ####################      #对文本的每一行计算词频的函数def processLine(line, wordCounts):  #用空格替换标点符号  line = replacePunctuations(line)  #从每一行获取每个词  words = line.split()   for word in words:    if word in wordCounts:      wordCounts[word] += 1    else:      wordCounts[word] = 1 #空格替换标点的函数def replacePunctuations(line):  for ch in line:    if ch in "~@#$%^&*()_-+=<>?/,.:;{}[]|/'""":      line = line.replace(ch, " ")  return line def main():  #用户输入一个文件名  filename = input("enter a filename:").strip()  infile = open(filename, "r")     #建立用于计算词频的空字典  wordCounts = {}  for line in infile:    processLine(line.lower(), wordCounts)       #从字典中获取数据对  pairs = list(wordCounts.items())   #列表中的数据对交换位置,数据对排序  items = [[x,y]for (y,x)in pairs]   items.sort()    #输出count个数词频结果  for i in range(len(items)-1, len(items)-count-1, -1):    print(items[i][1]+"/t"+str(items[i][0]))    data.append(items[i][0])    words.append(items[i][1])       infile.close()     #根据词频结果绘制柱状图  turtle.title('词频结果柱状图')  turtle.setup(900, 750, 0, 0)  t = turtle.Turtle()  t.hideturtle()  t.width(3)  drawGraph(t)  turtle.done()     #调用main()函数if __name__ == '__main__':  main()