Mixing string and base 64 with xml

Question

Hi i have problem because i wanted to have xml file with binary. The problem is with base64 encoding i dont knew how to encode image and add to string. I want after that parse this and decode image.

stringResult = ResultXMLTag.ROOT_BEGIN + '\n'

f = open('id_'+str(1)+'.png','rb+')

stringResult += ResultXMLTag.RESULT_BEGIN+' '+'ID=\'1\'>\n'
stringResult += ResultXMLTag.CDATA_BEGIN+'\n'
stringResult += base64.b64encode(f.read())

stringResult2 = '\n'+ ResultXMLTag.CDATA_END+'\n'
stringResult2 += ResultXMLTag.RESULT_END+'\n'
stringResult2 += ResultXMLTag.ROOT_END
    return stringResult + stringResult2

data = ET.fromstring(self.downloadData(connection))
for result in data.findall('./RESULT'):
    _id = result.get('ID')
    out = open('id_'+_id+'.png','wb+')
    out.write(base64.decode(result.findtext('').encode()))

EDIT error is in line with base64 "TypeError: Can't convert 'bytes' object to str implicitly"

EDIT example

>>> x = b'cat' + (base64.b64encode(b'dog'))
>>> x
b'catZG9n'

second version

>>> x = 'cat' + str(base64.b64encode(b'dog'))
>>> x
"catb'ZG9n'"

Witch version i should use to send image? I think all my problem are because how u append string and bytes. It simple to say encode image and then decode but this is not in my situation.

What is the problem? You should be able to concat a base64 encoded string with a non encoded string. Are you getting an error? What is it? — Sid, Jun 25 '13 at 15:47
TypeError: Can't convert 'bytes' object to str implicitly I dont knew why i cant concate that :/ — Luffy, Jun 25 '13 at 15:50

score 2 · Accepted Answer · answered Jun 25 '13 at 16:11

2

In Python 3, b64encode returns a byte string. You need to convert that to a Unicode string. The output is guaranteed to be ASCII bytes so the conversion is trivial.

stringResult += base64.b64encode(f.read()).decode('ascii')

answered Jun 25 '13 at 16:11

Mark Ransom

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score 0 · Answer 2 · answered Jun 25 '13 at 15:50

0

UPDATE: The problem could also be with downloadData(). Are you using urlopen()? Are you sure you are explicitly converting to string after you receive from downloadData()?

The problem could be with how you are creating your XML. In line:

stringResult += ResultXMLTag.RESULT_BEGIN+' '+'ID=\'1\'>\n'

Where are the quotes around the attribute "ID"?

Can you parse this XML without the IMAGE data? Concatenating a base 64 encoded string with a non-encoded string shouldn't cause any issues, they are both strings.

answered Jun 25 '13 at 15:50

Sid

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Yes i can parse without IMAGE data. Even with some other string. The quotes are to make ID='1' – Luffy Jun 25 '13 at 15:53
downloadData works. I have error with concating base64 to String. – Luffy Jun 25 '13 at 15:55
Is this python2 or python3? In python3 strings are all unicode. – Sid Jun 25 '13 at 16:05
Read this: http://stackoverflow.com/questions/10019268/decode-base64-string-in-python-3-with-lxml-or-not – Sid Jun 25 '13 at 16:07

Mixing string and base 64 with xml

2 Answers2