从网站获取pdf文件并写入磁盘

Question

I have some code reading a URL and writing to disk. Here it is -

    url = 'http://www.cs.purdue.edu/homes/ninghui/courses/Spring06/lectures/lecture05.pdf'
    ret = requests.get(url)
    print ret.headers
    print ret.headers['content-encoding']
    print ret.headers['content-type']

    pathToWrite = 'tmp/test.pdf'

    try:
        fd = os.open(pathToWrite, os.O_RDWR | os.O_CREAT)

        try:
            os.write(fd, ret.text)
        except Exception as e:
            print 'cannot write to file ' + pathToWrite
            raise

        try:
            os.close(fd)
        except:
            print 'cannot close file ' + pathToWrite
            raise

    except:
        print 'file cannot be opened ' + pathToWrite
        raise

With the above code I can get and write a pdf file to disk I get the following error -

UnicodeEncodeError: 'charmap' codec can't encode characters in position 12-13: character maps to <undefined>

I get the same error when I use the following API -

f = open(pathTowWrite, 'wb')
f.write(ret.text)

I feel like I am missing something obvious. This seems too straightforward to go wrong.

Answer 1

You want to write ret.content not ret.text . ret.text tries to conver the PDF to Unicode, which is probably impossible for a binary format like PDF.

Also, you can just use the builtin open function. No need for the low-level os.open here.