我目前有一个Django项目，具有查看功能，代码如下（代码复制自本文）：
from pylab import figure, axes, pie, title
from matplotlib.backends.backend_agg import FigureCanvasAgg
def test_matplotlib(request):
f = figure(1, figsize=(6,6))
ax = axes([0.1, 0.1, 0.8, 0.8])
labels = 'Frogs', 'Hogs', 'Dogs', 'Logs'
fracs = [15,30,45, 10]
explode=(0, 0.05, 0, 0)
pie(fracs, explode=explode, labels=labels, autopct='%1.1f%%', shadow=True)
title('Raining Hogs and Dogs', bbox={'facecolor':'0.8', 'pad':5})
canvas = FigureCanvasAgg(f)
response = HttpResponse(content_type='image/png')
canvas.print_png(response)
return response
它从一个图创建一个png并直接提供服务。如何在这个png中使图形的背景透明？
未经测试，但这应该有效。您不必写入（实际的）文件，类似文件的对象应该可以工作。此代码将图像保存到响应中。
def test_matplotlib(request):
f = figure(1, figsize=(6,6))
ax = axes([0.1, 0.1, 0.8, 0.8])
labels = 'Frogs', 'Hogs', 'Dogs', 'Logs'
fracs = [15,30,45, 10]
explode=(0, 0.05, 0, 0)
pie(fracs, explode=explode, labels=labels, autopct='%1.1f%%', shadow=True)
title('Raining Hogs and Dogs', bbox={'facecolor':'0.8', 'pad':5})
#canvas = FigureCanvasAgg(f)
response = HttpResponse(content_type='image/png')
f.savefig(response, transparent=True, format='png')
#canvas.print_png(response)
return response
