python怎么合并图表_使用ReportLab将两个图表合并到一个PDF中？

我使用Django和Reportlabs生成PDF格式的报告。我指的是this tutorial。在

我读了this thread和this thread，也就是说使用canv.showpage()，然后我就可以在1个pdf中组合2个图表，但是我仍然只得到代码中第二个图表，在我的例子中只有线图。在

如何将2个图表保存为1个pdf？在

这是我的密码。在import barchart

import linechart

from django.http import HttpResponse

from reportlab.graphics.shapes import Drawing

from reportlab.graphics.charts.barcharts import VerticalBarChart

from reportlab.graphics import renderPDF

from reportlab.pdfgen import canvas

def generate_report(request):

#instantiate a drawing object

canv = canvas.Canvas('output.pdf')#,pagesize=LETTER)

canv.setPageCompression(0)

d = barchart.MyBarChartDrawing()

#extract the request params of interest.

#I suggest having a default for everything.

if 'height' in request:

d.height = int(request['height'])

if 'width' in request:

d.width = int(request['width'])

if 'numbers' in request:

strNumbers = request['numbers']

numbers = map(int, strNumbers.split(','))

d.chart.data = [numbers] #bar charts take a list-of-lists for data

if 'title' in request:

d.title.text = request['title']

#get a GIF (or PNG, JPG, or whatever)

binaryStuff = d.asString('pdf')

#binaryStuff.save()

#return HttpResponse(binaryStuff, 'image/pdf')

#instantiate a drawing object

canv.showPage()

a = linechart.MyLineChartDrawing()

#extract the request params of interest.

#I suggest having a default for everything.

a.height = 300

a.chart.height = 300

a.width = 300

a.chart.width = 300

a.title._text = request.session.get('Some custom title')

a.XLabel._text = request.session.get('X Axis Labell')

a.YLabel._text = request.session.get('Y Axis Label')

a.chart.data = [((1,1), (2,2), (2.5,1), (3,3), (4,5)),((1,2), (2,3), (2.5,2), (3.5,5), (4,6))]

labels = ["Label One","Label Two"]

if labels:

# set colors in the legend

a.Legend.colorNamePairs = []

for cnt,label in enumerate(labels):

a.Legend.colorNamePairs.append((a.chart.lines[cnt].strokeColor,label))

#get a GIF (or PNG, JPG, or whatever)

binaryStuff1 = a.asString('pdf')

canv.showPage()

return HttpResponse(binaryStuff, 'pdf')

条形图和折线图代码与this site中的相同。在

如何保存在一个pdf文件中？在