使用reportlab python库生成孟加拉语PDF

我尝试在 BANGALA labguage 中生成 PDF。这里我添加了 Bangla Uni-Code 字体。但我的 PDF 生成不正确。在这里我添加代码片段和 Imag 的输出。为什么孟加拉语中的字体无法正常工作或 PDF 无法正确生成？

这是我的代码

import os
from io import BytesIO
from reportlab.lib import colors
from reportlab.lib.pagesizes import A4, inch, landscape
from reportlab.platypus import SimpleDocTemplate, Table, TableStyle, Paragraph, Frame
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.enums import TA_LEFT, TA_CENTER, TA_RIGHT, TA_JUSTIFY
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont
from django.http import HttpResponse


def download_pdf_file(request):

    # Create the HttpResponse object with the appropriate PDF headers.
    response = HttpResponse(content_type='application/pdf')
    response['Content-Disposition'] = 'attachment; filename="somefilename.pdf"'
    buffer = BytesIO()


    doc = SimpleDocTemplate(buffer, pagesize=A4, rightMargin=30, leftMargin=30, topMargin=30,
                            bottomMargin=18)
    doc.pagesize = landscape(A4)
    elements = []
    fontdiractory="/home/osman/font/"
    pdfmetrics.registerFont(TTFont('bangla', os.path.join(fontdiractory, 'Siyamrupali_1_01.ttf')))
    styles = getSampleStyleSheet()
    style_centre = ParagraphStyle(name='centre', parent=styles['Heading2'],fontName='bangla', alignment=TA_CENTER)

    p = Paragraph("গণপ্রজাতন্ত্রী বাংলাদেশ", style_centre)
    elements.append(p)
    p = Paragraph("UEO Office", style_centre)
    elements.append(p)
    p = Paragraph("Upazilla: "+'Tongipara'+ " District: "+'Gopalgonj', style_centre)
    elements.append(p)

    data = [
        ['Govt. Primary School','','','','','','',''],
        ['Ebtedaiye Madrasha','','','','','','',''],
        ['গণপ্রজাতন্ত্রী বাংলাদেশ','','','','','','',''],
        ['Primary school','','','','','','',''],
        ['Primary school','','','','','','',''],
        ['Primary school','','','','','','','']
    ]

    # TODO: Get this line right instead of just copying it from the docs
    style = TableStyle([('ALIGN', (1, 1), (-2, -2), 'RIGHT'),
                        ('TEXTCOLOR', (1, 1), (-2, -2), colors.red),
                        ('VALIGN', (0, 0), (0, -1), 'TOP'),
                        ('TEXTCOLOR', (0, 0), (0, -1), colors.blue),
                        ('ALIGN', (0, -1), (-1, -1), 'CENTER'),
                        ('VALIGN', (0, -1), (-1, -1), 'MIDDLE'),
                        ('TEXTCOLOR', (0, -1), (-1, -1), colors.green),
                        ('INNERGRID', (0, 0), (-1, -1), 0.25, colors.black),
                        ('BOX', (0, 0), (-1, -1), 0.25, colors.black),
                        ])

    data2 = [[Paragraph(cell, style_centre) for cell in row] for row in data]
    t = Table(data2)
    t.setStyle(style)
    elements.append(t)

    doc.build(elements)
    response.write(buffer.getvalue())
    buffer.close()
    return response

我可以看到默认的 canvas_basefontname 是“Helvetica”请参阅reportlab配置文档 https://github.com/eduardocereto/reportlab/blob/master/src/reportlab/rl_config.py所以我将 canvas_basefontname 更改为我所需的字体。就是这样。我在此添加以下代码link https://pairlist2.pair.net/pipermail/reportlab-users/2015-June/011391.html.

from reportlab import rl_config
rl_config._SAVED['canvas_basefontname'] = 'bangla'
rl_config._startUp()