Question

我有以下代码尝试从CSV文件创建字典，然后将CSV中每个“行”的值附加到PDF中的新页面。我正在使用pyPdf和ReportLab来实现这一目标。

源PDF包含2页，明信片的正面和背面，我试图为CSV文件中的每条记录复制。例如，包含25条记录的CSV文件将生成包含50页的PDF。（每个记录一个前面和一个后面）

我已经成功创建了具有适当页数的PDF，但是，我的代码中用于附加CSV文件中的值的部分为每个页面添加相同的值，而不是唯一值每页。

我很确定这与循环有关，因为打印字典会正确返回所有键和值对。我在这做错了什么？

d = {}                        
csv_file = open(filename, 'rb')
reader = csv.reader(csv_file)
rownum = 0
for row in reader:
    total_rows += 1
    page_count = (total_rows - 1)
    if rownum == 0:
        header = row
    else:
        colnum = 0
        for col in row:
            d[header[colnum]] = col
            colnum += 1

        packet = StringIO.StringIO()

        can = canvas.Canvas(packet, pagesize=(621,405))
        can.drawString(340, 147, d['FirstName'])
        can.save()

        packet.seek(0)
        new_pdf = PdfFileReader(packet)                        

        existing_pdf = PdfFileReader(file(order, 'rb'))
        output = PdfFileWriter()

        front = existing_pdf.getPage(0)
        back = existing_pdf.getPage(1)
        back.mergePage(new_pdf.getPage(0))
        for i in range(0, page_count):
            output.addPage(front)
            output.addPage(back)

        outputStream = file(token+'_merged.pdf', 'wb')
        output.write(outputStream)
        outputStream.close()

    rownum += 1

Answer 1

此循环为CSV中的每一行创建一个新文件，覆盖为早期行创建的版本。我并不完全熟悉您正在使用的库，但它看起来像是一种方法，可以在主循环外部保存outputStream来修复它：

output = PdfFileWriter()
for rownum, row in enumerate(reader):
    if rownum == 0:
        header = row
    else:
        for col in row:
            d[header[colnum]] = col
            colnum += 1
        # or, more concisely:
        # d = dict((header[colnum], value) for (colnum, value) in enumerate(row))
        # or use a dict comprehension if you're on a sufficiently recent version
        # or best of all, use a csv.DictReader object instead of creating the dictionary yourself

        packet = StringIO.StringIO()

        can = canvas.Canvas(packet, pagesize=(621,405))
        can.drawString(340, 147, d['FirstName'])
        can.save()

        packet.seek(0)
        new_pdf = PdfFileReader(packet)                        

        # I would check whether this can be read once and still have getPage called multiple times
        existing_pdf = PdfFileReader(file(order, 'rb'))

        front = existing_pdf.getPage(0)
        back = existing_pdf.getPage(1)
        back.mergePage(new_pdf.getPage(0))
        output.addPage(front)
        output.addPage(back)

outputStream = file(token+'_merged.pdf', 'wb')
output.write(outputStream)
outputStream.close()

正在应用字典中的相同值

1 个答案: