小编waq*_*ard的帖子

我正在尝试使用 DictReader 从 csv 文件中获取第一条记录作为 dict。我无法理解，因为文档只讨论迭代阅读器对象

 with open(filename, 'r') as f_in:
        # Use the csv library to set up a DictReader object.
        trip_reader = csv.DictReader(f_in)
        # Use a function on the DictReader object to read the
        # first trip from the data file and store it in a variable.
        for row in trip_reader:
                   pprint(row)

是否有任何函数可以将第一条记录作为trip_reader [0]？

我试图在某个位置将一些字符串写入PDF文件.我找到了一种方法来实现它并像这样实现:

from PyPDF2 import PdfFileWriter, PdfFileReader
import io
from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import letter

packet = io.StringIO()
# create a new PDF with Reportlab
can = canvas.Canvas(packet, pagesize=letter)
can.drawString(10, 100, "Hello world")
can.save()

#move to the beginning of the StringIO buffer
packet.seek(0)
new_pdf = PdfFileReader(packet)
# read your existing PDF
existing_pdf = PdfFileReader(file("original.pdf", "rb"))
output = PdfFileWriter()
# add the "watermark" (which is the new pdf) on the existing page
page = existing_pdf.getPage(0)
page.mergePage(new_pdf.getPage(0))
output.addPage(page)
# finally, write …