python设置pdf

导出：选用pdf

参考官方链接：https://wkhtmltopdf.org/usage/wkhtmltopdf.txt

设置导出的大小可以用page-size也可以直接page-wight，page-height：

Page sizes:
  The default page size of the rendered document is A4, but using this
  --page-size optionthis can be changed to almost anything else, such as: A3,
  Letter and Legal.  For a full list of supported pages sizes please see
  <http://qt-project.org/doc/qt-4.8/qprinter.html#PaperSize-enum>.

  For a more fine grained control over the page size the --page-height and
  --page-width options may be used