django 生成复杂的 PDF 文件（数据较多时）

如果您在创建一个复杂的 PDF 文档（或者任何较大的数据块），请使用 cStringIO 库存放临时生成的 PDF 文件。 cStringIO 提供了一个用 C 编写的类似文件对象的接口，从而可以使系统的效率最高。

from cStringIO import StringIO
from reportlab.pdfgen import canvas
from django.http import HttpResponse

def hello_pdf(request):
    # Create the HttpResponse object with the appropriate PDF headers.
    response = HttpResponse(mimetype='application/pdf')
    response['Content-Disposition'] = 'attachment; filename=hello.pdf'

    temp = StringIO()

    # Create the PDF object, using the StringIO object as its "file."
    p = canvas.Canvas(temp)

    # Draw things on the PDF. Here's where the PDF generation happens.
    # See the ReportLab documentation for the full list of functionality.
    p.drawString(100, 100, "Hello world.")

    # Close the PDF object cleanly.
    p.showPage()
    p.save()

    # Get the value of the StringIO buffer and write it to the response.
    response.write(temp.getvalue())
    return response