Base64 is an ascii encoding so you can just decode with ascii

>>> import base64
>>> example = b'\x01'*10
>>> example
b'\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01'
>>> result = base64.b64encode(example).decode('ascii')
>>> print(repr(result))
'AQEBAQEBAQEBAQ=='

I'm not sure I understand your question. I assume you are doing something along the lines of:

import base64

with open("yourfile.ext", "rb") as image_file:
    encoded_string = base64.b64encode(image_file.read())

You have to open the file first of course, and read its contents - you cannot simply pass the path to the encode function.

Edit: Ok, here is an update after you have edited your original question.

First of all, remember to use raw strings (prefix the string with 'r') when using path delimiters on Windows, to prevent accidentally hitting an escape character. Second, PIL's Image.open either accepts a filename, or a file-like (that is, the object has to provide read, seek and tell methods).

That being said, you can use cStringIO to create such an object from a memory buffer:

import cStringIO
import PIL.Image

# assume data contains your decoded image
file_like = cStringIO.StringIO(data)

img = PIL.Image.open(file_like)
img.show()

You have a script named base64.py which is shadowing the stdlib module. Rename it.

This line returns byte:

file_content=base64.b64decode(file_content)

Running this script in python3, it returned this exetion:

write() argument must be str, not bytes

You should convert bytes to string:

b"ola mundo".decode("utf-8") 

try it

import base64

file_content = 'b2xhIG11bmRv'
try:
   file_content=base64.b64decode(file_content)
   with open("data/q1.txt","w+") as f:
        f.write(file_content.decode("utf-8"))
except Exception as e:
   print(str(e))