TOCHeading1，具体怎么在reportlab中使用？

ReportLab是一个用于创建PDF文件的Python库。在ReportLab中使用TOCHeading1可以创建目录。下面是一个示例代码：

from reportlab.lib.styles import getSampleStyleSheet
from reportlab.platypus import SimpleDocTemplate, Paragraph

doc = SimpleDocTemplate("mydocument.pdf")
styles = getSampleStyleSheet()

# create the Table of Contents
toc = TableOfContents()

# add a heading to the Table of Contents
toc.levelStyles = [
    ParagraphStyle(fontName='Times-Bold', fontSize=14, name='TOCHeading1', leftIndent=20, firstLineIndent=-20, spaceBefore=10, leading=16),
    ParagraphStyle(fontName='Times-Bold', fontSize=12, name='TOCHeading2', leftIndent=40, firstLineIndent=-20, spaceBefore=5, leading=12),
]

# add a section to the Table of Contents
section = Section(
    Paragraph("Section 1", style=styles['TOCHeading1']),
    Paragraph("Section 2", style=styles['TOCHeading2']),
)
toc.append(section)

# build the document
doc.build([toc])

这个示例代码将创建一个名为“mydocument.pdf”的文档，其中包含一个目录，目录中有名为“Section 1”和“Section 2”的两个标题。