Error writing binary file in Python

Binary files have characters ASCII the file you are trying to record has Unicode you have converted before.

def chamaProg(arquivo): 
  var_file = open("C:\Nitgen\arquivo.rec","wb")
  conteudo_texto = var_file.write(arquivo.encode("utf-8"))
  var_file.close()

By taking a% w / o of missing% after% w / o (which I suppose was an error at the time of copying and pasting), your code is correct. Where does the ) variable come from? As you mentioned error 500 in another answer, I imagine this is part of a web application? I would investigate (even if spreading close( s by code) where this variable comes from; it is being prepared to be displayed on the web, not as a binary string.

If you can not avoid this transformation (because you do not control the code that calls your function), you can try the "dirty" solution of interpreting the input as an HTML snippet:

import HTMLParser
html_parser = HTMLParser.HTMLParser()
arquivo = html_parser.unescape(arquivo)

(but note that you should only use this to erase a production fire; you have to find out why arquivo is coming with these replacements)

You're having trouble with the encoding of these characters, so I recommend opening the file as utf8 . You can do this with the built-in codecs package . Here's an example:

# -*- coding: utf-8 -*-
import codecs


def save_file(content):
    with codecs.open('file.rec', 'wb', 'utf8') as f:
        f.write(content)

if __name__ == '__main__':
    save_file(u'ÐT_Ö/¤Ð樮kMµûÀz”Ô(Î,“+œd¼Es¥')

And another tip, whenever you're working with files, use context manager with this example), because it already closes the file for you when you leave the context.