Reportlab不在Google App Engine上的Django应用程序中生成图表

Question

我有一个在Google应用程序引擎上运行的django应用程序。该应用程序的一个功能是根据在使用应用程序时向其提供的数据生成图表。我使用reportlab生成图表，并在开发过程中使用。然而，在上传应用程序到谷歌应用程序引擎，任何试图查看图表页面返回以下错误：

“在导入错误... 无模块名为_renderPM”

到目前为止，我有据悉，该错误是由于reportlab对GAE不支持的PIL的依赖造成的。我已将reportlab模块放置在应用程序的项目目录中，但仍然无效。

因此，我的问题是：我需要做什么才能使图表在应用程序中可见？无论如何，按照我的应用程序的要求，让reportlab在GAE上工作吗？

（的用于该应用程序的 “mycharts.py” 和 “views.py” 码如下所示。）

mycharts.py

from reportlab.graphics.shapes import Drawing, String 
from reportlab.graphics.charts.barcharts import VerticalBarChart 
from reportlab.graphics.charts.linecharts import HorizontalLineChart 
from reportlab.graphics.charts.lineplots import LinePlot 
from reportlab.graphics.widgets.markers import makeMarker 
from reportlab.graphics.charts.textlabels import Label 
from reportlab.graphics.widgets.grids import Grid, DoubleGrid 
from reportlab.lib import colors 
from models import Caller 

#Customer gender filter functions begin here 
def male_caller_count(): 
    return Caller.objects.filter(gender='Male').count() 

def female_caller_count(): 
    return Caller.objects.filter(gender='Female').count() 
#Customer gender filter functions end here 

class GenderChartDraw(Drawing): 
    def __init__(self, width=500, height=500, *args, **kw): 

     Drawing.__init__(self,width,height,*args,**kw) 

     female = female_caller_count() 
     male = male_caller_count() 

     data = [(male, 0), (0, female)] 

     self.add(VerticalBarChart(), name='chart') 
     self.add(String(100,450,'Caller by Gender'), name='title') 
     self.title.fontName = 'Helvetica-Bold' 
     self.title.fontSize = 20 

     self.chart.x = 70 
     self.chart.y = 20 
     self.chart.width = 300 
     self.chart.height = 400 
     self.chart.data = data 
     self.chart.strokeColor = colors.black 
     self.chart.valueAxis.valueMin = 0 
     self.chart.valueAxis.valueMax = 50 
     self.chart.valueAxis.valueStep = 5 
     self.chart.valueAxis.visibleGrid = 1 
     self.chart.categoryAxis.style = 'stacked' 
     self.chart.categoryAxis.categoryNames = ['Male', 'Female'] 
     self.chart.bars[0].fillColor = colors.HexColor('#376BF9') 
     self.chart.bars[1].fillColor = colors.HexColor('#FE03E5') 
     self.chart.categoryAxis.labels.fontSize = 13 

if __name__=='__main__': 
    #use the standard 'save' method to save barchart.gif, barchart.pdf etc 
    #for quick feedback while working. 
    GenderChartDraw().save(formats=['gif','png','jpg','pdf'],outDir='.',fnRoot='barchart') 

views.py

from django.shortcuts import render, render_to_response 
from django.http import HttpResponse, HttpResponseRedirect 
from django.template import RequestContext 
from django.views.decorators.csrf import csrf_exempt 
from datetime import datetime 
from models import Caller 
import mycharts 
from django.contrib.auth.decorators import login_required 

@login_required 
def app_stats(request): 
    return render_to_response('AppStats.html', context_instance=RequestContext(request)) 

@login_required 
def gender_chart(request): 
    #instantiate a drawing object 
    d = mycharts.GenderChartDraw() 

    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('gif') 
    return HttpResponse(binaryStuff, 'image/gif') 

错误日志

ImportError at /CallApp/stats/GenderChart/ 
No module named _renderPM 
see https://www.reportlab.com/software/opensource/rl-addons/ 
Request Method: GET 
Request URL: http://cacallapp.appspot.com/CallApp/stats/GenderChart/ 
Django Version: 1.4.3 
Exception Type: ImportError 
Exception Value:  
No module named _renderPM 
see https://www.reportlab.com/software/opensource/rl-addons/ 
Exception Location: /base/data/home/apps/s~cacallapp/1.365898222031464318/reportlab/graphics/renderPM.py in <module>, line 32 
Python Executable: /python27_runtime/python27_dist/python 
Python Version: 2.7.3 
Python Path:  
['/base/data/home/apps/s~cacallapp/1.365898222031464318', 
'/python27_runtime/python27_dist/lib/python27.zip', 
'/python27_runtime/python27_dist/lib/python2.7', 
'/python27_runtime/python27_dist/lib/python2.7/plat-linux2', 
'/python27_runtime/python27_dist/lib/python2.7/lib-tk', 
'/python27_runtime/python27_dist/lib/python2.7/lib-old', 
'/python27_runtime/python27_dist/lib/python2.7/lib-dynload', 
'/python27_runtime/python27_dist/lib/python2.7/site-packages', 
'/python27_runtime/python27_lib/versions/1', 
'/python27_runtime/python27_lib/versions/third_party/PIL-1.1.7', 
'/python27_runtime/python27_lib/versions/third_party/PIL-1.1.7/PIL', 
'/python27_runtime/python27_lib/versions/third_party/django-1.4', 
'/python27_runtime/python27_lib/versions/third_party/webapp2-2.3', 
'/python27_runtime/python27_lib/versions/third_party/webob-1.1.1', 
'/python27_runtime/python27_lib/versions/third_party/yaml-3.10', 
'/base/data/home/apps/s~cacallapp/1.365898222031464318/..'] 
Server time: Tue, 12 Mar 2013 08:38:21 +0000 

回溯

/python27_runtime/python27_lib/versions/third_party/django-1.4/django/core/handlers/base.py in get_response 
         response = callback(request, *callback_args, **callback_kwargs) ... 
▶ Local vars 
/python27_runtime/python27_lib/versions/third_party/django-1.4/django/contrib/auth/decorators.py in _wrapped_view 
       return view_func(request, *args, **kwargs) ... 
▶ Local vars 
/base/data/home/apps/s~cacallapp/1.365898222031464318/CallApp/views.py in gender_chart 
    binaryStuff = d.asString('gif') 
... 
▶ Local vars 
/base/data/home/apps/s~cacallapp/1.365898222031464318/reportlab/graphics/shapes.py in asString 
      from reportlab.graphics import renderPM 
... 
▶ Local vars 
/base/data/home/apps/s~cacallapp/1.365898222031464318/reportlab/graphics/renderPM.py in <module> 
            "see https://www.reportlab.com/software/opensource/rl-addons/") 
... 
▶ Local vars 

Answer 1

由于许多应用程序不需要它，默认情况下未安装PIL。尝试安装PIL：

https://developers.google.com/appengine/docs/python/images/installingPIL

另外，你在你的app.yaml指定PIL：

libraries: 
- name: PIL 
    version: "latest"