ReportLab：如何从段落的左上点开始写作，因为默认情况下它是从左下点

Question

from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import A4 
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont
from reportlab.lib.styles import ParagraphStyle
from reportlab.lib.styles import getSampleStyleSheet
from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, PageBreak
from reportlab.lib.enums import TA_JUSTIFY, TA_LEFT, TA_CENTER, TA_RIGHT

pdfmetrics.registerFont(TTFont('Dejavu', 'DejaVuSansCondensed.ttf'


packet_1 = io.BytesIO()
can = canvas.Canvas(packet_1, pagesize=A4)
styles = getSampleStyleSheet()
styleN = styles["BodyText"]


my_style = ParagraphStyle(name ='My style',
                          fontName='Dejavu',
                          fontSize=12,
                          alignment=TA_LEFT,
                          borderWidth = 1,
                          borderColor = 'black'
                          )

p3 = Paragraph('''abdc''', my_style)
p3.wrapOn(can, 500, 100)
p3.drawOn(can, 10, 300)

无论段落高度如何，文本都从底部开始。 如何使其从顶部开始？

Answer 1

添加bottoRP = 0 exp：exp：

...
can = canvas.Canvas(packet_1, pagesize=A4, bottomup=0)
...

Answer 2

免责声明我是borb的作者。

BORB是一个纯Python PDF库，既可以提供低级（您可以在哪个确切的坐标内容中使用）和高级（Borb照顾布局）为您）模型。

您可以查看示例，在段落对齐中有整个部分。您可以发现在这里。

在示例中，段落在精确的坐标处添加，并使用各种Alignment参数布置。

我将在此处复制相关示例的完整性：

from borb.pdf.document.document import Document
from borb.pdf.page.page import Page
from borb.pdf.canvas.layout.text.paragraph import Paragraph
from borb.pdf.pdf import PDF
from borb.pdf.canvas.geometry.rectangle import Rectangle
from borb.pdf.canvas.layout.layout_element import Alignment
from borb.pdf.canvas.layout.annotation.square_annotation import SquareAnnotation
from borb.pdf.canvas.color.color import HexColor

from decimal import Decimal


def main():
    # create Document
    doc: Document = Document()

    # create Page
    page: Page = Page()

    # add Page to Document
    doc.append_page(page)

    # define layout rectangle
    # fmt: off
    r: Rectangle = Rectangle(
        Decimal(59),                # x: 0 + page_margin
        Decimal(848 - 84 - 100),    # y: page_height - page_margin - height_of_textbox
        Decimal(595 - 59 * 2),      # width: page_width - 2 * page_margin
        Decimal(100),               # height
    )
    # fmt: on

    # this is a quick hack to easily get a rectangle on the page
    # which can be very useful for debugging
    page.append_annotation(SquareAnnotation(r, stroke_color=HexColor("#ff0000")))

    # the next line of code uses absolute positioning
    Paragraph("Hello World!", vertical_alignment=Alignment.TOP).layout(page, r)

    # store
    with open("output.pdf", "wb") as pdf_file_handle:
        PDF.dumps(pdf_file_handle, doc)


if __name__ == "__main__":
    main()

这应该产生以下PDF：

我在段落周围添加了一个红色矩形，以说明内容实际上是用vertaltical_alignment verticaltic_alignment < /code>设置为alignment.top。