最近有網友求助一個分析紅酒資料畫柱形圖的問題，之前沒畫過柱形圖，所以特意去研究了一下。

分享一下畫柱形圖的方法，以下是程式碼：

# -*- coding:utf8 -*-

import matplotlib.pyplot as plt
from numpy import *
import random
import csv

def ParseWineData():#解析資料
    countryList = []
    pointList = []
    with open('winemag-data_first150k.csv') as csvfile:
        csv_reader = csv.reader(csvfile)  # 使用csv.reader讀取csvfile中的檔案
        for row in csv_reader:  # 將csv 檔案中的資料儲存到birth_data中
            countryList.append(row[1])
            pointList.append(row[4])
    countryList.remove(countryList[0])
    pointList.remove(pointList[0])
    csvfile.close()
    # fr = open('winemag-data_first150k.csv')#普通方法讀取資料
    # allLinesArr = fr.readlines()
    # for line in allLinesArr:
    #     line = line.strip()
    #     lineList = line.split(',')
    #     countryList.append(lineList[1])
    return countryList, pointList

def CreateVocabList(dataSet):#建立資料集的並集
    vocabList = []
    for i in range(len(dataSet)):
        if dataSet[i] in vocabList:
            continue
        else:
            if len(dataSet[i]) < 20 and dataSet[i] != '':
                vocabList.append(dataSet[i])
    return vocabList

def CountCountryNum(countryList, countryVocabList, pointList):#計算各國家好的紅酒佔比
    countryNumList = [0 for _ in range(len(countryVocabList))]#國家出現總次數
    pointNinetyFiveList = [0 for _ in range(len(countryVocabList))]#紅酒高於95分次數
    precentList = [0 for _ in range(len(countryVocabList))]#95分紅酒在當前國家佔比

    for i in range(len(countryList)):
        for j in range(len(countryVocabList)):
            if countryList[i] == countryVocabList[j]:
                countryNumList[j] = countryNumList[j] + 1#計算國家出現次數
                if (int(pointList[i])) >= 95:
                    pointNinetyFiveList[j] = pointNinetyFiveList[j] + 1#計算高分紅酒次數
    for k in range(len(precentList)):
        precentList[k] = pointNinetyFiveList[k] *100.0/ countryNumList[k]#計算百分比
    return precentList

def DrawBarChart(nameList, precentList):#畫柱形圖
    randomColorList = []
    for i in range(len(nameList)):
        rNum = str(hex(random.randint(0, 255))) if str(hex(random.randint(0, 255)))==4 else str(hex(random.randint(0, 255)))+"0"
        gNum = str(hex(random.randint(0, 255))) if str(hex(random.randint(0, 255)))==4 else str(hex(random.randint(0, 255)))+"0"
        bNum = str(hex(random.randint(0, 255))) if str(hex(random.randint(0, 255)))==4 else str(hex(random.randint(0, 255)))+"0"
        randomColor = str('#'+rNum[2:4]+gNum[2:4]+bNum[2:4])#建立隨機顏色
        randomColorList.append(randomColor)
    plt.title("95-Point Wine In Countrys")
    rects = plt.bar(range(len(precentList)), precentList, 1, color = randomColorList[:])
    # X軸標題
    indexList = [i for i in range(len(precentList))]
    plt.xticks(indexList, nameList, rotation = 90)
    plt.xlabel("Countrys")  # X軸標籤
    plt.ylim(ymax=5.0, ymin=0.0)
    plt.ylabel("95-Point Wine Precent(%)")  # Y軸標籤
    for rect in rects:
        height = rect.get_height()
        height = float("%.2f" %height)
        plt.text(rect.get_x() + rect.get_width()*0.6, height+0.15, str(height)+"%" , ha='center', va='bottom', rotation = 90)
    plt.show()

countryList, pointList = ParseWineData()
countryVocabList = CreateVocabList(countryList)
precentList = CountCountryNum(countryList, countryVocabList, pointList)
print countryVocabList
DrawBarChart(countryVocabList, precentList)
 

程式碼很短，只有79行，可以看出python程式碼的特有的簡潔和便捷的功能，還有matplotlib圖形庫的強大之處。

執行以後，畫出柱形圖：