使用Pycairo，我创建了一个“SVGSurface”（为我创建了一个svg文件），然后使用“context”编写它。在我完成之后，我需要使用svg文件，但似乎文件没有关闭，所以它给我一个错误，告诉文档是空的。
ps = cairo.SVGSurface("header.svg", width, height)
cr = cairo.Context(ps)
drawRectangle (cr,
papersize.convert_length(int(lg[0]), "px","pt"),
papersize.convert_length(int(lg[2]), "px","pt"),
papersize.convert_length(int(lg[1])-int(lg[0])-1, "px","pt"),
papersize.convert_length(int(lg[3])-int(lg[2])-1, "px","pt"),
0, 0, 0.5
)
cr.show_page()
head = st.fromfile("header.svg")
它给了我这个错误：
File "/usr/local/lib/python2.7/dist-packages/svgutils/transform.py", line 249, in fromfile
svg_file = etree.parse(fid)
File "src/lxml/lxml.etree.pyx", line 3427, in lxml.etree.parse (src/lxml/lxml.etree.c:81117)
File "src/lxml/parser.pxi", line 1832, in lxml.etree._parseDocument (src/lxml/lxml.etree.c:118116)
File "src/lxml/parser.pxi", line 1852, in lxml.etree._parseFilelikeDocument (src/lxml/lxml.etree.c:118399)
File "src/lxml/parser.pxi", line 1747, in lxml.etree._parseDocFromFilelike (src/lxml/lxml.etree.c:117187)
File "src/lxml/parser.pxi", line 1162, in lxml.etree._BaseParser._parseDocFromFilelike (src/lxml/lxml.etree.c:111914)
File "src/lxml/parser.pxi", line 595, in lxml.etree._ParserContext._handleParseResultDoc (src/lxml/lxml.etree.c:105109)
File "src/lxml/parser.pxi", line 706, in lxml.etree._handleParseResult (src/lxml/lxml.etree.c:106817)
File "src/lxml/parser.pxi", line 635, in lxml.etree._raiseParseError (src/lxml/lxml.etree.c:105671)
lxml.etree.XMLSyntaxError: Document is empty, line 1, column 1 (line 1)
我试图用操作系统关闭文件，但它无法正常工作