How do I convert esp.flash_read() to string - esp8266

I have the following code:
buff=esp.flash_read(esp.flash_user_start(),50)
print(buff)
I get the following output from print:
bytearray(b'{"ssid": "mySSID", "password": "myPASSWD"}\xff\xff\xff\xff\xff\xff')
What I want to do is get the json in buff. What is the correct "Python-way" to do that?

buff is a Python bytes object, as shown by the print output beginning with b'. To convert this into a string you need to decode it.
In standard Python you could use
buff.decode(errors='ignore')
Note that without specifying errors=ignore you would get a UnicodeDecodeError because the \xff bytes aren't valid in the default encoding, which is UTF-8; presumably they're padding and you want to ignore them.
If that works on the ESP8266, great! However this from the MicroPython docs suggests the keyword syntax might not be implemented - I don't have an ESP8266 to test it. If not then you may need to remove the padding characters yourself:
textLength = find(buff, b'\xff')
text = buff[0:textLength].decode()
or simply:
text = buff[0:buff.find(b'\xff')].decode()
If decode isn't implemented either, which it isn't in the online MicroPython interpreter, you can use str:
text = str(buff[0:find(buff, b'\xff')], 'utf-8')
Here you have to specify explicitly that you're decoding from UTF-8 (or whatever encoding you specify).
However if what you're really after is the values encoded in the JSON, you should be able to use the json module to retrieve them into a dict:
import json
j = json.loads(buff[0:buff.find(b'\xff')])
ssid = j['ssid']
password = j['password']

Related

uint64 to hex in lua 5.1

Hey I am not able to make this conversion correctly. I use below code
RawGUID=17379524724484210731 --It's impossible to store variable this way, it will always convert into test3 eventually. Stored as userdata I cannot change
test1="17379524724484210731"
test2="1.7379524724484e+019"
test3=1.7379524724484e+019
function tohex(num)
local charset = {"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"}
local tmp = {}
repeat
table.insert(tmp,1,charset[num%16+1])
num = math.floor(num/16)
until num==0
return table.concat(tmp)
end
RawGUID is an example of what I need to convert into hex string, the rest of the variables is just conversion of the same number.
The code works well for anything that's below 64bits.
To be honest, to achieve my goal I need a string in hex to make the rest of my code work
The result I am getting: F13079A800000000
The result I want: F13079A80000002B

Extra slash ( \ ) getting added when string (with unicode character) added to a dictionary

I am facing the following issue:
In my app, the user can enter special characters (like emojis) in a textfield also. So, while sending this entered text to server in request body, I am converting it using the following code:
func emojiToUTF8()->String
{
let data = self.data(using: .nonLossyASCII, allowLossyConversion: true)
let emoji = String.init(data: data!, encoding: .utf8)
return emoji ?? self
}
For instance, if I enter the text "☺️", it gets converted into "\u263a\ufe0f" using the above method. Things are fine till here.
The problem occurs when I add this to a dictionary for sending it as a request parameter to the server. Code i'm using:
var parameters = [String:String]()
parameters["feedback"] = feedBackTxt
print("Parameters:",parameters) /// output: ["feedback": "\\u263a\\ufe0f"]
So, the problem here is that an extra slash is getting appended before each slash due to char escaping. I checked the created dictionary value as well. It shows double slash there also. How do I avoid this? Why is this happening when I am simply creating a dictionary with a string? This is causing issue at server end.
I have tried a couple of things, but none of them seem to work.
Your problem is that you're double-encoding.
You're taking a string, converting it to ASCII, then re-parsing it as UTF8 and then encoding that (probably) as JSON, which is UTF8. In the process, the backslashes are being escaped by your second encoder.
The best solution to this is to rework your server to accept UTF8. However, if you can't do that, you need to ensure you encode this string just one time, in ASCII.
In short, you should get rid of emojiToUTF8 and ensure that your parameters processor encodes the way your server requires (which apparently is ASCII and not UTF8).

Unicode characters returning from R.NET

I'm returning a Character vector from a function in R to C# using R.NET. The only problem is that unicode characters, such as Greek Letters are being lost. The following line gives an example of the code I'm using:
CharacterVector cvAll = results[5].AsList().AsCharacter();
Where results is a list of results returned by the R function. The characters are also written by R to a text file and they display fine in notepad and other editors. Can I get R.Net to return the characters correctly?
Looks like you ran into an open issue with RDotNet : https://github.com/jmp75/rdotnet/issues/25
Unicode characters don't seem to be supported yet. I ran into the same issue while calling the engine.CreateDataFrame() method. It did return a DataFrame with all my accentuated strings wrong.
There seems to be a workaround though : when calling RDotNet functions, if I give strings encoded in my computer default encoding (Windows ANSI) and converted from UTF-8 (important), R takes them and gives back correctly interpreted accentuated strings to C#. I don't exactly know why it is working though... It might have something to do with the default encoding used with .Net for string being UTF-16. (cf. here : http://csharpindepth.com/Articles/General/Strings.aspx), hence the conversion from UTF-8 to default ANSI that seems to be working.
Here is an ugly example : when I'm building a RDotNet DataFrame, I convert all strings in a CharacterVector to ANSI (from UTF-8) encoded ones :
try
{
string[] colAsStrings = null;
colAsStrings = Array.ConvertAll<object, string>(uneColonne, s => StringEncodingHelper.EncodeToDefaultFromUTF8((string)s));
correctedDataArray[i] = colAsStrings;
columnConverted = true;
}
Here is the static method used for conversion :
public static string EncodeToDefaultFromUTF8(string stringToEncode)
{
byte[] utf8EncodedBytes = Encoding.UTF8.GetBytes(stringToEncode);
return Encoding.Default.GetString(utf8EncodedBytes);
}

Decode UTF-8 String Swift iOS

I am trying to decode a string which is in UTF-8 format, into normal human readable string and tried may codes available on SO. But non of these worked.
My demo UTF-8 String is :-
let demoString: String = "यॠपहलॠपहलॠà¤à¤¾à¤¹à¤¤à¤¯à¥ बहà¤à¥ बहà¤à¥ हालत"
Is there is anyway to decode this UTF-8 String in swift. Any help would be appricated.
let demoString: String = "यॠपहलॠपहलॠà¤à¤¾à¤¹à¤¤à¤¯à¥ बहà¤à¥ बहà¤à¥ हालत"
This defines a perfectly fine string containing some rather weird characters like "à", "¤" and so on. There is no decoding that can be done here. The first character is a "Latin Small Letter A With Grave", U+00E0 or C3A0 in UTF-8 format.
If you want a string with "Hindi" characters - I suppose you mean Devanagari, or Bengali, Gurmukhi, Gujarati etc. , type for example
let demoString: String = "ऄइउऋऌऍ"

How to remove non-ascii char from MQ messages with ESQL

CONCLUSION:
For some reason the flow wouldn't let me convert the incoming message to a BLOB by changing the Message Domain property of the Input Node so I added a Reset Content Descriptor node before the Compute Node with the code from the accepted answer. On the line that parses the XML and creates the XMLNSC Child for the message I was getting a 'CHARACTER:Invalid wire format received' error so I took that line out and added another Reset Content Descriptor node after the Compute Node instead. Now it parses and replaces the Unicode characters with spaces. So now it doesn't crash.
Here is the code for the added Compute Node:
CREATE FUNCTION Main() RETURNS BOOLEAN
BEGIN
DECLARE NonPrintable BLOB X'0001020304050607080B0C0E0F101112131415161718191A1B1C1D1E1F7F808182838485868788898A8B8C8D8E8F909192939495969798999A9B9C9D9E9FA0A1A2A3A4A5A6A7A8A9AAABACADAEAFB0B1B2B3B4B5B6B7B8B9BABBBCBDBEBFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECFD0D1D2D3D4D5D6D7D8D9DADBDCDDDEDFE0E1E2E3E4E5E6E7E8E9EAEBECEDEEEFF1F2F3F4F5F6F7F8F9FAFBFCFDFEFF';
DECLARE Printable BLOB X'20202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020';
DECLARE Fixed BLOB TRANSLATE(InputRoot.BLOB.BLOB, NonPrintable, Printable);
SET OutputRoot = InputRoot;
SET OutputRoot.BLOB.BLOB = Fixed;
RETURN TRUE;
END;
UPDATE:
The message is being parsed as XML using XMLNSC. Thought that would cause a problem, but it does not appear to be.
Now I'm using PHP. I've created a node to plug into the legacy flow. Here's the relevant code:
class fixIncompetence {
function evaluate ($output_assembly,$input_assembly) {
$output_assembly->MRM = $input_assembly->MRM;
$output_assembly->MQMD = $input_assembly->MQMD;
$tmp = htmlentities($input_assembly->MRM->VALUE_TO_FIX, ENT_HTML5|ENT_SUBSTITUTE,'UTF-8');
if (!empty($tmp)) {
$output_assembly->MRM->VALUE_TO_FIX = $tmp;
}
// Ensure there are no null MRM fields. MessageBroker is strict.
foreach ($output_assembly->MRM as $key => $val) {
if (empty($val)) {
$output_assembly->MRM->$key = '';
}
}
}
}
Right now I'm getting a vague error about read only messages, but before that it wasn't working either.
Original Question:
For some reason I am unable to impress upon the senders of our MQ
messages that smart quotes, endashes, emdashes, and such crash our XML
parser.
I managed to make a working solution with SQL queries, but it wasted
too many resources. Here's the last thing I tried, but it didn't work
either:
CREATE FUNCTION CLEAN(IN STR CHAR) RETURNS CHAR BEGIN
SET STR = REPLACE('–',STR,'–');
SET STR = REPLACE('—',STR,'—');
SET STR = REPLACE('·',STR,'·');
SET STR = REPLACE('“',STR,'“');
SET STR = REPLACE('”',STR,'”');
SET STR = REPLACE('‘',STR,'&lsqo;');
SET STR = REPLACE('’',STR,'’');
SET STR = REPLACE('•',STR,'•');
SET STR = REPLACE('°',STR,'°');
RETURN STR;
END;
As you can see I'm not very good at this. I have tried reading about
various ESQL string functions without much success.
So in ESQL you can use the TRANSLATE function.
The following is a snippet I use to clean up a BLOB containing non-ASCII low hex values so that it then be cast into a usable character string.
You should be able to modify it to change your undesired characters into something more benign. Basically each hex value in NonPrintable gets translated into its positional equivalent in Printable, in this case always a full-stop i.e. x'2E' in ASCII. You'll need to make your BLOB's long enough to cover the desired range of hex values.
DECLARE NonPrintable BLOB X'000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F303132333435363738393A3B3C3D3E3F';
DECLARE Printable BLOB X'2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E2E';
SET WorkBlob = TRANSLATE(WorkBlob, NonPrintable, Printable);
BTW if messages with invalid characters only come in every now and then I'd probably specify BLOB on the input node and then use something similar to the following to invoke the XMLNSC parser.
CREATE LASTCHILD OF OutputRoot DOMAIN 'XMLNSC'
PARSE(InputRoot.BLOB.BLOB CCSID InputRoot.Properties.CodedCharSetId ENCODING InputRoot.Properties.Encoding);
With the exception terminal wired up you can then correct the BLOB's of any messages containing parser breaking invalid characters before attempting to reparse.
Finally my best wishes as I've had a number of battles over the years with being forced to correct invalid message content in the "Integration Layer" after all that's what it's meant to do.

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