How to add a character before a string?

Question

I am new and I'm trying to insert a character before a string.

If I have a string like so:

'wB0JSYuEUshUkgpKi8TRTwv/EABgBAQADAQAAAAAAA'

I want to add b before the string but not part of the string-like so:

b'wB0JSYuEUshUkgpKi8TRTwv/EABgBAQADAQAAAAAAA'

Here's what I tried:

test = 'b' + words[1]
test

but this obviously returns the b within the string, which is not what I want.

What's the use case? The `b` isn't part of the string itself, but a marker for a *literal* of type `bytes`. If you just need a `bytes` value, use `test = words.encode()`. — chepner, Apr 27 '20 at 14:50

score 5 · Accepted Answer · answered Apr 27 '20 at 14:49

5

That b is not part of the string, it's a special syntax in Python 3.x to indicate that it's a bytes literal (see this post). If you want to convert a "normal" string into a bytes literal, do this:

st = 'abc'
bl = st.encode()

bl
=> b'abc'

answered Apr 27 '20 at 14:49

Óscar López

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score 0 · Answer 2 · answered Apr 27 '20 at 14:50

0

I'm not exactly sure what you mean. But assuming words is a list of strings, and index 1 = 'wB0JSYuEUshUkgpKi8TRTwv/EABgBAQADAQAAAAAAA' you could print(f'b {words[1]}')

answered Apr 27 '20 at 14:50

Oliver Robie

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Yea I wasn't sure if OP was asking to literally insert a character, or to convert to bytes – Oliver Robie Apr 27 '20 at 14:55

score 0 · Answer 3 · answered Apr 27 '20 at 14:52

There is a bit of confusion here. In python "" is a string and b"" is a byte string. These are completely different objects. They can be converted to one another, but they are not the same thing. You can't add "b to a string". Essentially a byte string b"" is a string of the bytes that generate a string, and a string is well the string. For example,

x = 'STRING'   #The string itself. 
y = x.encode() #The bytes for the string. Note that ascii bytes are written in ascii. 

a = 'MyName®'  #The string itself.
b = a.encode() #The bytes for the string. The last character takes two non-ascii bytes. 
c = b.decode() #Covert the bytes back to a string.

How to add a character before a string?

3 Answers3