如何更正TypeError：在使用ReportLab进行散列之前，必须对Unicode对象进行编码

Question

最近，我一直在工作。目前，我想使用ReportLab生成PDF格式的可点击目录

当我试图了解它是如何工作的时，我不断得到这个错误：TypeError: Unicode-objects must be encoded before hashing

当我试图使用ReportLab库在Python 3.7.4上执行此代码时：

class MyDocTemplate(BaseDocTemplate):
    def __init__(self, filename, **kw):
        self.allowSplitting = 0
        apply(BaseDocTemplate.__init__, (self, filename), kw)
        template = PageTemplate('normal', [Frame(2.5*cm, 2.5*cm, 15*cm, 25*cm, id='F1')])
        self.addPageTemplates(template)


    def afterFlowable(self, flowable):
        "Registers TOC entries."
        if flowable.__class__.__name__ == 'Paragraph':
            text = flowable.getPlainText()
            style = flowable.style.name
            if style == 'Heading1':
                level = 0
            elif style == 'Heading2':
                level = 1
            else:
                return
            E = [level, text, self.page]
            #if we have a bookmark name append that to our notify data
            bn = getattr(flowable,'_bookmarkName',None)
            if bn is not None: E.append(bn)
            self.notify('TOCEntry', tuple(E))

centered = PS(name = 'centered',
    fontSize = 30,
    leading = 16,
    alignment = 1,
    spaceAfter = 20)

h1 = PS(
    name = 'Heading1',
    fontSize = 14,
    leading = 16)


h2 = PS(name = 'Heading2',
    fontSize = 12,
    leading = 14)


# Build story.
story = []

toc = TableOfContents()
toc.levelStyles = [
    PS(fontName='Times-Bold', fontSize=20, name='TOCHeading1', leftIndent=20, firstLineIndent=-20, spaceBefore=10, leading=16),
    PS(fontSize=18, name='TOCHeading2', leftIndent=40, firstLineIndent=-20, spaceBefore=5, leading=12),
]
story.append(toc)

def doHeading(text,sty):
    from hashlib import sha1
    #create bookmarkname
    bn=sha1(text+sty.name).hexdigest()
    #modify paragraph text to include an anchor point with name bn
    h=Paragraph(text+'<a name="%s"/>' % bn,sty)
    #store the bookmark name on the flowable so afterFlowable can see this
    h._bookmarkName=bn
    story.append(h)

story.append(Paragraph('<b>Table of contents</b>', centered))
story.append(PageBreak())
doHeading('First heading', h1)
story.append(Paragraph('Text in first heading', PS('body')))
doHeading('First sub heading', h2)
story.append(Paragraph('Text in first sub heading', PS('body')))
story.append(PageBreak())
doHeading('Second sub heading', h2)
story.append(Paragraph('Text in second sub heading', PS('body')))
story.append(PageBreak())
doHeading('Last heading', h1)
story.append(Paragraph('Text in last heading', PS('body')))
doc = MyDocTemplate('mintoc.pdf')
doc.multiBuild(story)

我试图解决此问题，但无法正确解决此问题。谢谢你在这方面的帮助

Answer 1

您应该传递字节，而不是字符串，因此问题在于：

bn=sha1(text+sty.name).hexdigest()

你能做的就是这样改变它：

bn=sha1((text+sty.name).encode("utf8")).hexdigest()

另外，您应该将sha1导入移到文件的顶部，无需每次运行函数时都调用它