How to split "\t" in a string to two separate characters as "\" and "t"? (How to split Escape Sequence?) [duplicate]

Question

I am trying to split a string in python into a list of characters. I know that there are a lot of ways to do this in python, but I have a case where those methods don't give me the desired results.

The problem happens when I have special characters like '\t' that is explicitly written in the string (and I don't mean the real tab).

Example:

string = "    Hello \t World."

the output I need is:

list_of_chars = [' ', ' ', ' ', ' ', 'H', 'e', 'l', 'l', 'o', ' ', '\', 't', ' ', 'W', 'o', 'r', 'l', 'd', '.']

but when I use the methods that are given in this question, I get a list that contains '/t' as whole string - not separated.

Example:

> list(string)
> ['H', 'e', 'l', 'l', 'o', 'w', ' ', '\t', ' ', 'W', 'o', 'r', 'l', 'd', '.']

I want to know why this happens and how to get what I want.

Answer 1

You can substitute your string accordingly:

import itertools
txt = "    Hello \t World."

specials = { 
    '\a' : '\\a', #     ASCII Bell (BEL)
    '\b' : '\\b', #     ASCII Backspace (BS)
    '\f' : '\\f', #     ASCII Formfeed (FF)
    '\n' : '\\n', #     ASCII Linefeed (LF)
    '\r' : '\\r', #     ASCII Carriage Return (CR)
    '\t' : '\\t', #     ASCII Horizontal Tab (TAB)
    '\v' : '\\v'  #     ASCII Vertical Tab (VT)
}

# edited out: # txt2 = "".join([x if x not in specials else specials[x] for x in txt])
txt2 = itertools.chain(* [(list(specials[x]) if x in specials else [x]) for x in txt])

print(list(txt2))

Output:

[' ', ' ', ' ', ' ', 'H', 'e', 'l', 'l', 'o', ' ', '\\', 't', ' ', 'W', 
 'o', 'r', 'l', 'd', '.'] 

The list comprehension looks more "positive" and uses list(itertools.chain(*[...])) instead of list("".join([...])) which should be more performant.