[python] How to convert a string to utf-8 in Python

I have a browser which sends utf-8 characters to my Python server, but when I retrieve it from the query string, the encoding that Python returns is ASCII. How can I convert the plain string to utf-8?

NOTE: The string passed from the web is already UTF-8 encoded, I just want to make Python to treat it as UTF-8 not ASCII.

Yes, You can add

# -*- coding: utf-8 -*-

in your source code's first line.

You can read more details here https://www.python.org/dev/peps/pep-0263/

If the methods above don't work, you can also tell Python to ignore portions of a string that it can't convert to utf-8:

stringnamehere.decode('utf-8', 'ignore')

• First, str in Python is represented in Unicode.
• Second, UTF-8 is an encoding standard to encode Unicode string to bytes. There are many encoding standards out there (e.g. UTF-16, ASCII, SHIFT-JIS, etc.).

When the client sends data to your server and they are using UTF-8, they are sending a bunch of bytes not str.

You received a str because the "library" or "framework" that you are using, has implicitly converted some random bytes to str.

Under the hood, there is just a bunch of bytes. You just need ask the "library" to give you the request content in bytes and you will handle the decoding yourself (if library can't give you then it is trying to do black magic then you shouldn't use it).

• Decode UTF-8 encoded bytes to str: bs.decode('utf-8')
• Encode str to UTF-8 bytes: s.encode('utf-8')

Might be a bit overkill, but when I work with ascii and unicode in same files, repeating decode can be a pain, this is what I use:

def make_unicode(input):
    if type(input) != unicode:
        input =  input.decode('utf-8')
    return input

city = 'Ribeir\xc3\xa3o Preto'
print city.decode('cp1252').encode('utf-8')

Adding the following line to the top of your .py file:

# -*- coding: utf-8 -*-

allows you to encode strings directly in your script, like this:

utfstr = "????"

If I understand you correctly, you have a utf-8 encoded byte-string in your code.

Converting a byte-string to a unicode string is known as decoding (unicode -> byte-string is encoding).

You do that by using the unicode function or the decode method. Either:

unicodestr = unicode(bytestr, encoding)
unicodestr = unicode(bytestr, "utf-8")

Or:

unicodestr = bytestr.decode(encoding)
unicodestr = bytestr.decode("utf-8")

In Python 3.6, they do not have a built-in unicode() method. Strings are already stored as unicode by default and no conversion is required. Example:

my_str = "\u221a25"
print(my_str)
>>> v25

Translate with ord() and unichar(). Every unicode char have a number asociated, something like an index. So Python have a few methods to translate between a char and his number. Downside is a ñ example. Hope it can help.

>>> C = 'ñ'
>>> U = C.decode('utf8')
>>> U
u'\xf1'
>>> ord(U)
241
>>> unichr(241)
u'\xf1'
>>> print unichr(241).encode('utf8')
ñ