python - convert binary data to utf-8

Question

_f = open("c:/go-next.png", "rb")
data = _f.read()
_f.close()
data.encode("utf-8")

# Error: UnicodeDecodeError: file <maya console> line 1: ascii # 

As you see I open a image file, and the data is type. But I have to convert it to utf-8. Maybe binary data has some extra char (or not), it conflict with conversion. Is there any way to solve it?

Solution 1

Text encodings only apply to text. Do not attempt to use them on binary data.

Solution 2

You can always map a str to unicode using the latin-1 codec. Once you have a unicode, you can always encode it in utf-8:

data.decode('latin-1').encode("utf-8")

Solution 3

What you're trying to accomplish can probably be achieved by base64 encoding it.

 import base64
 encoded = base64.b64encode(image_binary_data)

Comments

[yantrab]

I don't mean to be blunt, but converting a PNG to UTF8 doesn't make any sense. PNG is an image format. UTF8 is a text encoding. Can you explain more what it is you are trying to do?

[Esailija]

@Hyun-geunKim using code in that link, you would add_file for the image, and add_field for text. .add_file("my_image", "go-next.png", open("c:/go-next.png", "rb"), "image/png") and for text .add_field("key", "text")

[Ignacio Vazquez-Abrams]

While this is true, the result has no meaning.

[unutbu]

Without meaning? A supercomputer was once asked, "What is the meaning of life?" I'm pretty sure it answered, '42'.decode('latin1').encode('utf-8'). :-)

[Hyun-geun Kim]

Yes, I and my colleague set up another POST module.

[yingted]

@IgnacioVazquez-Abrams The latin-1 codec maps codepoints "0-255 to the bytes 0x0-0xff": docs.python.org/2/library/codecs.html#encodings-and-unicode So, this does exactly what you'd expect.

[Ignacio Vazquez-Abrams]

@yingted: I'm pretty sure that converting 0xd0 to 0xc3 0x90 atc. will corrupt the image, which is hardly what you'd want.

[yingted]

@IgnacioVazquez-Abrams I just hit this. I have to transfer a blob across a UTF-8 channel, but I don't have a base64 decoder on the receiving side. This would be the correct answer if the question made any sense.