Add "b" prefix to python variable?

Question

Adding the prefix "b" to a string converts it to bytes:

b'example'

But I can't figure out how to do this with a variable. Assuming string = 'example', none of these seem to work:

b(string)
b string
b'' + string

Is there a simple way to do this?

• Leonardo.Z: b converts str to bytes,not binary
• zombio: whoops you're correct. Changed it.

Answer 1

# only an example, you can choose a different encoding
bytes('example', encoding='utf-8')

In Python3:

Bytes literals are always prefixed with 'b' or 'B'; they produce an instance of the bytes type instead of the str type. They may only contain ASCII characters; bytes with a numeric value of 128 or greater must be expressed with escapes.

In Python2:

A prefix of 'b' or 'B' is ignored in Python 2; it indicates that the literal should become a bytes literal in Python 3.

More about bytes():

bytes([source[, encoding[, errors]]])

Return a new "bytes" object, which is an immutable sequence of integers in the range 0 <= x < 256. bytes is an immutable version of bytearray – it has the same non-mutating methods and the same indexing and slicing behavior.

Accordingly, constructor arguments are interpreted as for bytearray().

Bytes objects can also be created with literals, see String and Bytes literals.

• Grant Gubatan: so how should you do it in python 2?
• Nabin: If I don't know the encoding of a string, then?

Answer 2

Use bytes():

>>> bytes("hello", encoding="ascii")
b'hello'

Answer 3

You can use the bytes.decode() method to convert bytes to string (using a given encoding):

>>> b'hello'.decode('utf-8')
'hello'

The opposite conversion is str.encode() to convert a string to bytes:

>>> 'hello'.encode('utf-8')
b'hello'

Answer 4

string = bytes(string, encoding= 'utf-8')

where 'string' is your variable.

Answer 5

I have checked for this for long time and i think the best way to convert a string into a varible is using vars()

vars()['variable name'] = value to assign

vars()['created_variable'] = 1
print(created_variable)
>> 1