Convert Python Bytes to String Without Encoding

Question

I am using Python 3.6 and I have an image as bytes:

img = b'\xff\xd8\xff\xe0\x00\x10JFIF\x00'

I need to convert the bytes into a string without encoding so it looks like:

raw_img = '\xff\xd8\xff\xe0\x00\x10JFIF\x00'

The goal is to incorporate this into an html image tag:

<img src="'data:image/png;base64," + base64.b64encode(raw_img) + "' />"

Answer 1

Why not just call str and remove the b after?

In:

str(img)[2:-1]

Out:

'\xff\xd8\xff\xe0\x00\x10JFIF\x00'

Answer 2

img.decode("utf-8")

You can decode the variable with the above. Then convert it to base64.

"<img src='data:image/png;base64,{}'/>".format( base64.b64encode(img.decode("utf-8")) )

UPDATED:

What you really want is this:

raw_img = repr(img)
"<img src='data:image/png;base64,{}'/>".format( base64.b64encode(raw_img) )

Answer 3

Since you just need to convert the image to string why not just use str() function?

>>> img = b'\xff\xd8\xff\xe0\x00\x10JFIF\x00'
>>> type(img)
<class 'bytes'>
>>>
>>>raw_img = str(img)
>>> type(str(img)) 
<class 'str'>
>>>

img is in bytes, but when you use str() it is converted to type string.

An encoding can also be specified https://docs.python.org/3/library/stdtypes.html#str, which would be a more natural way to do things:

str(img, encoding='ansi')

As suggested in these answers

Answer 4

I'm pretty sure img is the byte string that you want to pass to base64.b64encode:

>>> import base64
>>> img = b'\xff\xd8\xff\xe0\x00\x10JFIF\x00'
>>> base64.b64encode(img)
b'/9j/4AAQSkZJRgA='

If you want to incorporate that into an HTML string, use

html = b'<img src="data:image/png;base64,' + base64.b64encode(img) + b' />'

Answer 5

I didn't solve this but here's some research on it(3Feb2022): This encoding is latin (or latin-1) and it's hard to print because Python wants to print it in another format. But for your case they should be the same. And for a data:image/png;base64 base64 code should be used.

My test code:

import codecs

img = b"\xff\xd8\xff\xe0\x00\x10JFIF\x00"
desired = "\xff\xd8\xff\xe0\x00\x10JFIF\x00"
str_decode = img.decode("latin-1")
str_decode_2 = str(img, "latin-1")
codecs_decode = codecs.decode(img, "latin-1")
print(desired.encode("latin-1") == img)
print(str_decode == desired)
print(str_decode == str_decode_2)
print(str_decode == codecs_decode)
print("desired:", repr(desired))  ##devprint

This gives 4 True and a desired: ÿØÿà\x00\x10JFIF\x00 with Python 3.10.

Answer 6

I've solved it (2022 - bit late to the party...) If you try img_raw.decode() you get the UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 0: invalid start byte error

But if you leave img_raw as a binary string and pass it into b64encode and then decode it, it doesn't have the UnicodeDecodeError, and you can pass it in as a data string to your image tag.

base64.b64encode(raw_image).decode()