这个项目比较简单，介绍了ReportLab的用法。
首先要用到的是画折线类，PolyLine，用法很简单，看下面的例子：
1 from reportlab.lib import colors 2 from reportlab.graphics.shapes import* 3 from reportlab.graphics import renderPDF 4 5 drawing = Drawing(200, 150) 6 drawing.add(PolyLine([(50, 50), (100, 50), (100, 100), (50, 100), (50, 50)])) 7 8 renderPDF.drawToFile(drawing, ‘report2.pdf‘, ‘Sunsports‘)
1 from reportlab.lib import colors 2 from reportlab.graphics.shapes import* 3 from reportlab.graphics import renderPDF 4 5 data=[ 6 # Year Month Predicted High Low 7 (2007, 8, 113.2, 114.2, 112.2), 8 (2007, 9, 112.8, 115.8, 109.8), 9 (2007, 10, 111.0, 116.0, 106.0), 10 (2007, 11, 109.8, 116.8, 102.8), 11 (2007, 12, 107.3, 115.3, 99.3), 12 (2008, 1, 105.2, 114.2, 96.2), 13 (2008, 2, 104.1, 114.1, 94.1), 14 (2008, 3, 99.9, 110.9, 88.9), 15 (2008, 4, 94.8, 106.8, 82.8), 16 (2008, 5, 91.2, 104.2, 78.2) 17 ] 18 19 drawing = Drawing(200, 150) 20 21 pred = [row[2]-40 for row in data] 22 high = [row[3]-40 for row in data] 23 low = [row[4]-40 for row in data] 24 times = [200*((row[0]+row[1]/12.0)-2007)-110 for row in data] 25 26 drawing.add(PolyLine(list(zip(times, pred)), strokeColor = colors.blue)) 27 drawing.add(PolyLine(list(zip(times, high)), strokeColor = colors.red)) 28 drawing.add(PolyLine(list(zip(times, low)), strokeColor = colors.green)) 29 drawing.add(String(65, 115, ‘Sunspots‘, fontSize=18, fillColor = colors.red)) 30 31 renderPDF.drawToFile(drawing, ‘report1.pdf‘, ‘Sunsports‘)
这儿需要注意的一点是书上的写法是：
PolyLine(zip(times, pred), strokeColor = colors.blue)
但是在python3中这样写是错误的，会有 TypeError: object of type ‘zip‘ has no len() 错误。可以改写成上述写法。
接下来是进阶版本，不难：
1 from urllib.request import urlopen #python3中在request中 2 from reportlab.graphics.shapes import * 3 from reportlab.graphics.charts.lineplots import LinePlot 4 from reportlab.graphics.charts.textlabels import Label 5 from reportlab.graphics import renderPDF 6 7 URL = ‘http://services.swpc.noaa.gov/text/predicted-sunspot-radio-flux.txt‘ 8 COMMENT_CHARS = ‘#:‘ 9 10 drawing = Drawing(400, 200) 11 data = [] 12 13 for line in urlopen(URL).readlines(): 14 line = line.decode() #这儿需要这样做，否则下面无法转化成float，具体不太清楚。。。 15 if not line.isspace() and not line[0] in COMMENT_CHARS: 16 data.append([float(n) for n in line.split()]) 17 18 pred = [row[2] for row in data] 19 high = [row[3] for row in data] 20 low = [row[4] for row in data] 21 times = [row[0] + row[1]/12.0 for row in data] 22 23 lp = LinePlot() 24 lp.x = 50 25 lp.y = 50 26 lp.height = 120 27 lp.width = 300 28 29 lp.data =[tuple(zip(times, pred)), tuple(zip(times, high)), tuple(zip(times, low))] #这儿最后也要转换成元组 30 31 lp.lines[0].strokeColor = colors.red 32 lp.lines[1].strokeColor = colors.blue 33 lp.lines[2].strokeColor = colors.green 34 35 drawing.add(lp) 36 drawing.add(String(250, 150, ‘Sunspots‘, fontSize =14, fillColor = colors.red)) 37 38 renderPDF.drawToFile(drawing, ‘report2.pdf‘, ‘Sunspots‘)
