Trying To Create Table To Braille In Python

Question

I've Been Trying To Create A System Which Turns A Table Of 1's And 0's To A Braille Character But It Keeps Giving Me This Error

File "brail.py", line 16 stringToWrite=u"\u"+brail([1,1,1,0,0,0,1,1]) ^ SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 0-1: truncated \uXXXX escape

My Current Code Is

def brail(brailList):
    if len(brailList) == 8:
        brailList.reverse()
        brailHelperList=[0x80,0x40,0x20,0x10,0x8,0x4,0x2,0x1]
        brailNum=0x0
        for num in range(len(brailList)):
            if brailList[num] == 1:
                brailNum+=brailHelperList[num]
        stringToReturn="28"+str(hex(brailNum))[2:len(str(hex(brailNum)))]
        return stringToReturn
    else:
        return "String Needs To Be 8 In Length"

fileWrite=open('Write.txt','w',encoding="utf-8")
stringToWrite=u"\u"+brail([1,1,1,0,0,0,1,1])
fileWrite.write(stringToWrite)
fileWrite.close()

It Works When I Do fileWrite.write(u"\u28c7") But When I Do A Function Which Should Return That Exact Same Thing It Errors.

Image Of Code Just In Case

Can you fix the indentation of your code? If the entire code block that you posted is part of your function, everything including and after ```fileWrite=open()``` will not run (it is after a return statement). — goalie1998, Feb 07 '21 at 07:29
Sorry I fixed the indentation for some reason stackoverflow messed it up — Joshua66252, Feb 07 '21 at 07:37

mhawke · Accepted Answer · 2021-02-07T08:14:59.187

1

\u is the unicode escape sequence for Python literal strings. A 4 hex digit unicode code point is expected to follow the escape sequence. It is a syntax error if the code point is missing or is too short.

>>> '\u28c7'
'⣇'

>>> '\u'
  File "<stdin>", line 1
    '\u'
        ^
SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 0-1: truncated \uXXXX escape

If you are using Python 3 then the u string prefix is not required as strings are stored as unicode internally. The u prefix was maintained for compatibility with Python 2 code.

That's the cause of the exception, however, you don't need to construct the unicode code point like that. You can use the ord() and chr() functions:

    from unicodedata import lookup
    braille_start = ord(lookup('BRAILLE PATTERN BLANK'))
    return chr(braille_start + brailNum)

edited Feb 07 '21 at 08:14

answered Feb 07 '21 at 07:37

mhawke

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Is There Any Way To Make It So That It Can Take The Four Characters From The Function, It Would Be Very Helpful As I Need It To Make The Unicode Character From The Set Of Numbers Provided. – Joshua66252 Feb 07 '21 at 07:43
@Joshua66252: see my update that requires no string manipulation. – mhawke Feb 07 '21 at 07:54
Do You Know How To Mark An Answer As Correct? Edit: Wait Figured It Out – Joshua66252 Feb 07 '21 at 07:57
Wait Sorry To Mark This As Incorrect Again But When I Feed 10299 Into The chr Function It Outputs та╗ When It Should Output ⠻ Do You Know How I Can Fix This? @mhawke – Joshua66252 Feb 07 '21 at 08:31
It's working for me so it's probably a display issue with your terminal. What is your terminal encoding? `print(sys.getdefaultencoding())`. You can check the value with: `unicodedata.name(chr(10299))` is BRAILLE PATTERN DOTS-12456 – mhawke Feb 07 '21 at 08:55
As I Am Writing To A File I Don't Think The Terminal Is The Issue. Whats Your Python Ver. Mines Python 3.8.5 Edit: I Just Looked And My Python Is Outdated I'm Going To Update And See If That Fixes It – Joshua66252 Feb 07 '21 at 09:03
I Updated Python To Python 3.9.1 And It Still Outputs та╗ Whats Your Python Ver – Joshua66252 Feb 07 '21 at 09:13
OK, good point. It's not your Python version. – mhawke Feb 07 '21 at 09:14
Just To Make Sure Though Can You Please Send Your Python Ver Just In Case It Is Something To Do With Version – Joshua66252 Feb 07 '21 at 09:16
3.9. You don't have to capitalise all of your words :). – mhawke Feb 07 '21 at 09:17
This is my current code btw https://pastebin.com/raw/K7UtyMYE just in case its something I'm messing up on EDIT: Sorry for capping every word it's a bad habit that I have. – Joshua66252 Feb 07 '21 at 09:20
How are you viewing the output file? Because you are converting to UTF8 the unicode characters will be output as a UTF8 byte stream which is a sequence of 3 bytes for code point 10299. It will be the terminal encoding that is not decoding/displaying the file correctly. – mhawke Feb 07 '21 at 09:21
I am viewing the outputted file with Notepad++ – Joshua66252 Feb 07 '21 at 09:22
I Just Opened It In A Hex Editor And The Hex Is E2 A0 BB Its Probably Something To Do With The Python chr Function Not What I'm Viewing It With. – Joshua66252 Feb 07 '21 at 09:38
No, that is the correct byte sequence. `b'\xe2\xa0\xbb'.decode('utf8')` is `⠻`. Make sure that you open it as UTF8 in Notepad. – mhawke Feb 07 '21 at 09:41
I Thought 283B Was ⠻ Not E2 A0 BB Also Notepad++ Not Notepad – Joshua66252 Feb 07 '21 at 09:45
Also I Just Checked And The Encoding Is Already Set To UTF-8 – Joshua66252 Feb 07 '21 at 09:46
0x283B is the Unicode code point for BRAILLE PATTERN DOTS-12456. E2 A0 BB is the UTF8 encoding of that code point. Try this to aid your understanding: `print(chr(0x283B))` and `print(chr(0x283B).encode('utf8'))` – mhawke Feb 07 '21 at 09:52
Is There Any Way I Can Make it Write To The TXT As A Unicode Code Point Instead Of A UTF8 Encoding? – Joshua66252 Feb 07 '21 at 09:55
Yes. Set the encoding to UTF16. You can read up on the basics of Unicode, here's one place to start https://www.joelonsoftware.com/2003/10/08/the-absolute-minimum-every-software-developer-absolutely-positively-must-know-about-unicode-and-character-sets-no-excuses/ – mhawke Feb 07 '21 at 09:58
Thank You I'll Respond With The Link To The Finished Code Once I'm Done So That Other People Can See This Post If They Need It. – Joshua66252 Feb 07 '21 at 10:00
Oh I Literally Just Changed The Encoding From The Code I Posted Earlier To UTF-16 And It Started Working Perfectly Without Any Of The Issues From Earlier I'm Going To Post It As An Answer. – Joshua66252 Feb 07 '21 at 11:00

score 0 · Answer 2 · answered Feb 07 '21 at 07:47

0

You can rewrite

stringToWrite=u"\u"+brail([1,1,1,0,0,0,1,1])

as

stringToWrite="\\u{0}".format(brail([1, 1, 1, 0, 0, 0, 1, 1]))

All strings are unicode in Python 3, so you don't need the leading "u".

answered Feb 07 '21 at 07:47

goalie1998

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That Makes The File Say \u28c7 Currently I Want The File To Have The Character ⣇ – Joshua66252 Feb 07 '21 at 07:50

Joshua66252 · Answer 3 · 2021-02-07T12:09:42.413

def braille(brailleString):
    brailleList = []
    brailleList[:0]=brailleString
    if len(brailleList) > 8:
        brailleList=brailleList[0:8]
    if len(brailleList) < 8:
        while len(brailleList) < 8:
            brailleList.append('0')
    brailleList1=[
    int(brailleList[0]),
    int(brailleList[1]),
    int(brailleList[2]),
    int(brailleList[4]),
    int(brailleList[5]),
    int(brailleList[6]),
    int(brailleList[3]),
    int(brailleList[7]),
    ]
    brailleList1.reverse()
    brailleHelperList=[128,64,32,16,8,4,2,1]
    brailleNum=0
    for num in range(len(brailleList1)):
        if brailleList1[num] == 1:
            brailleNum+=brailleHelperList[num]
    brailleStart = 10240
    return chr(brailleStart+brailleNum)
fileWrite=open('Write.txt','w',encoding="utf-16")
fileWrite.write(braille('11111111'))
fileWrite.close()

# Think Of The Braille Functions String Like It Has A Seperator In The Middle And The 1s And 0s Are Going Vertically

Working Answer But You Cannot Accept More Than 1. – Joshua66252 Feb 10 '21 at 20:46 — Joshua66252, Feb 10 '21 at 20:46

Trying To Create Table To Braille In Python

3 Answers3