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How to avoid problem with encode UTF-8 error

I've got problem with reading text files. When I start program and add file, it throws an error:
Traceback (most recent call last):
File "c:/Users/Marcin/Desktop/python/graf_menu.py", line 38, in <module>
main_func()
File "c:/Users/Marcin/Desktop/python/graf_menu.py", line 32, in main_func
read_file()
File "c:/Users/Marcin/Desktop/python/graf_menu.py", line 15, in read_file
for i in f.read():
File "C:\Users\Marcin\AppData\Local\Programs\Python\Python38-32\lib\codecs.py", line 322, in decode
(result, consumed) = self._buffer_decode(data, self.errors, final)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb3 in position 19: invalid start byte
In my code there is a line with "encoding="UTF-8". How to solve the problem. The code below:
files = input("File name: ")
try:
with open(files,"r",encoding="UTF-8") as f:
for i in f.read():
print(i,end='')
except FileNotFoundError:
print("FileNotFoundError")

There is nothing wrong with the program itself. You are getting this error because you are trying to read a file which is not encoded as UTF-8 as UTF-8-encoded. You have to either convert the contents of the file to UTF-8 or specify a different encoding (the one that the file actually uses) in the call to open.

This file is not encoded as UTF-8 try to use encoded="iso-8859-1"

anaconda-navigator not running after a abrupt shutdown

I was running anaconda-navigator in the past days. My system was abruptly shutdown one day. After that, when I run anaconda-navigator, it is showing the following error
dstlab2#dstlab2-Veriton-M200-H81:~$ anaconda-navigator
Traceback (most recent call last):
File "/home/dstlab2/anaconda3/bin/anaconda-navigator", line 11, in <module>
sys.exit(main())
File "/home/dstlab2/anaconda3/lib/python3.7/site-packages/anaconda_navigator/app/main.py", line 99, in main
from anaconda_navigator.utils.logs import clean_logs
File "/home/dstlab2/anaconda3/lib/python3.7/site-packages/anaconda_navigator/utils/logs.py", line 18, in <module>
from anaconda_navigator.config import (LOG_FILENAME, LOG_FOLDER,
File "/home/dstlab2/anaconda3/lib/python3.7/site-packages/anaconda_navigator/config/__init__.py", line 27, in <module>
from anaconda_navigator.config.main import CONF
File "/home/dstlab2/anaconda3/lib/python3.7/site-packages/anaconda_navigator/config/main.py", line 71, in <module>
raw_mode=True,
File "/home/dstlab2/anaconda3/lib/python3.7/site-packages/anaconda_navigator/config/user.py", line 221, in __init__
self.load_from_ini()
File "/home/dstlab2/anaconda3/lib/python3.7/site-packages/anaconda_navigator/config/user.py", line 279, in load_from_ini
self.read(self.filename(), encoding='utf-8')
File "/home/dstlab2/anaconda3/lib/python3.7/configparser.py", line 696, in read
self._read(fp, filename)
File "/home/dstlab2/anaconda3/lib/python3.7/configparser.py", line 1014, in _read
for lineno, line in enumerate(fp, start=1):
File "/home/dstlab2/anaconda3/lib/python3.7/codecs.py", line 322, in decode
(result, consumed) = self._buffer_decode(data, self.errors, final)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xf2 in position 378: invalid continuation byte
can anyone help me how to set things right?

It looks as if a configuration file used by anaconda navigator has been corrupted. The file probably exists in the $HOME/.anaconda folder; it may have a .ini extension.
If you can identify the file, you could try replacing the byte that's causing the problem (make a backup copy of the file first):
>>> with open('config.ini', 'rb+') as f:
... data = f.read()
... data = data.replace(b'\xf2', b'')
... assert data
... f.seek(0)
... f.write(data)
...
0
171
Note that there may be more than one byte.
It's also possible that the file has been truncated or corrupted so much that it needs to be deleted or replaced entirely.

Umlauts in JSON files lead to errors in Python code created by ANTLR4

I've created python modules from the JSON grammar on github / antlr4 with
antlr4 -Dlanguage=Python3 JSON.g4
I've written a main program "JSON2.py" following this guide: https://github.com/antlr/antlr4/blob/master/doc/python-target.md
and downloaded the example1.json also from github.
python3 ./JSON2.py example1.json # works perfectly, but
python3 ./JSON2.py bookmarks-2017-05-24.json # the bookmarks contain German Umlauts like "ü"
...
File "/home/xyz/lib/python3.5/site-packages/antlr4/FileStream.py", line 27, in readDataFrom
return codecs.decode(bytes, encoding, errors)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 227: ordinal not in range(128)
The offending line in JSON2.py is
input = FileStream(argv[1])
I've searched stackoverflow and tried this instead of using the above FileStream:
fp = codecs.open(argv[1], 'rb', 'utf-8')
try:
input = fp.read()
finally:
fp.close()
lexer = JSONLexer(input)
stream = CommonTokenStream(lexer)
parser = JSONParser(stream)
tree = parser.json() # This is line 39, mentioned in the error message
Execution of this program ends with an error message, even if the input file doesn't contain Umlauts:
python3 ./JSON2.py example1.json
Traceback (most recent call last):
File "./JSON2.py", line 46, in <module>
main(sys.argv)
File "./JSON2.py", line 39, in main
tree = parser.json()
File "/home/x/Entwicklung/antlr/links/JSONParser.py", line 108, in json
self.enterRule(localctx, 0, self.RULE_json)
File "/home/xyz/lib/python3.5/site-packages/antlr4/Parser.py", line 358, in enterRule
self._ctx.start = self._input.LT(1)
File "/home/xyz/lib/python3.5/site-packages/antlr4/CommonTokenStream.py", line 61, in LT
self.lazyInit()
File "/home/xyz/lib/python3.5/site-packages/antlr4/BufferedTokenStream.py", line 186, in lazyInit
self.setup()
File "/home/xyz/lib/python3.5/site-packages/antlr4/BufferedTokenStream.py", line 189, in setup
self.sync(0)
File "/home/xyz/lib/python3.5/site-packages/antlr4/BufferedTokenStream.py", line 111, in sync
fetched = self.fetch(n)
File "/home/xyz/lib/python3.5/site-packages/antlr4/BufferedTokenStream.py", line 123, in fetch
t = self.tokenSource.nextToken()
File "/home/xyz/lib/python3.5/site-packages/antlr4/Lexer.py", line 111, in nextToken
tokenStartMarker = self._input.mark()
AttributeError: 'str' object has no attribute 'mark'
This parses correctly:
javac *.java
grun JSON json -gui bookmarks-2017-05-24.json
So the grammar itself is not the problem.
So finally the question: How should I process the input file in python, so that lexer and parser can digest it?
Thanks in advance.

Make sure your input file is actually encoded as UTF-8. Many problems with character recognition by the lexer are caused by using other encodings. I just took a testbed application, added ëto the list of available characters for an IDENTIFIER and it works again. UTF-8 is the key -- and make sure your grammar also allows these characters where you want to accept them.

I solved it by passing the encoding info:
input = FileStream(sys.argv[1], encoding = 'utf8')
If without the encoding info, I will have the same issue as yours.
Traceback (most recent call last):
File "test.py", line 20, in <module>
main()
File "test.py", line 9, in main
input = FileStream(sys.argv[1])
File ".../lib/python3.5/site-packages/antlr4/FileStream.py", line 20, in __init__
super().__init__(self.readDataFrom(fileName, encoding, errors))
File ".../lib/python3.5/site-packages/antlr4/FileStream.py", line 27, in readDataFrom
return codecs.decode(bytes, encoding, errors)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe4 in position 1: ordinal not in range(128)
Where my input data is
[今明]天(台南|高雄)的？天氣如何

Unicode problems in Python again

I have a strange problem. A friend of mine sent me a text file. If I copy/paste the text and then paste it into my text editor and save it, the following code works. If I choose the option to save the file directly from the browser, the following code breaks. What's going on? Is it the browser's fault for saving invalid characters?
This is an example line.
When I save it, the line says
What�s going on?
When I copy/paste it, the line says
What’s going on?
This is the code:
import codecs
def do_stuff(filename):
with codecs.open(filename, encoding='utf-8') as f:
def process_line(line):
return line.strip()
lines = f.readlines()
for line in lines:
line = process_line(line)
print line
do_stuff('stuff.txt')
This is the traceback I get:
Traceback (most recent call last):
File "test-encoding.py", line 13, in <module>
do_stuff('stuff.txt')
File "test-encoding.py", line 8, in do_stuff
lines = f.readlines()
File "/home/somebody/.python/lib64/python2.7/codecs.py", line 679, in readlines
return self.reader.readlines(sizehint)
File "/home/somebody/.python/lib64/python2.7/codecs.py", line 588, in readlines
data = self.read()
File "/home/somebody/.python/lib64/python2.7/codecs.py", line 477, in read
newchars, decodedbytes = self.decode(data, self.errors)
UnicodeDecodeError: 'utf8' codec can't decode byte 0x92 in position 4: invalid start byte
What can I do in such cases?
How can I distribute the script if I don't know what encoding the user who runs it will use?
Fixed:
codecs.open(filename, encoding='utf-8', errors='ignore') as f:

The "file-oriented" part of the browser works with raw bytes, not characters. The specific encoding used by the page should be specified either in the HTTP headers or in the HTML itself. You must use this encoding instead of assuming that you have UTF-8 data.

Converting domain names to idn in python

I have a long list of domain names which I need to generate some reports on. The list contains some IDN domains, and although I know how to convert them in python on the command line:
>>> domain = u"pfarmerü.com"
>>> domain
u'pfarmer\xfc.com'
>>> domain.encode("idna")
'xn--pfarmer-t2a.com'
>>>
I'm struggling to get it to work with a small script reading data from the text file.
#!/usr/bin/python
import sys
infile = open(sys.argv[1])
for line in infile:
print line,
domain = unicode(line.strip())
print type(domain)
print "IDN:", domain.encode("idna")
print
I get the following output:
$ ./idn.py ./test
pfarmer.com
<type 'unicode'>
IDN: pfarmer.com
pfarmerü.com
Traceback (most recent call last):
File "./idn.py", line 9, in <module>
domain = unicode(line.strip())
UnicodeDecodeError: 'ascii' codec can't decode byte 0xfc in position 7: ordinal not in range(128)
I have also tried:
#!/usr/bin/python
import sys
import codecs
infile = codecs.open(sys.argv[1], "r", "utf8")
for line in infile:
print line,
domain = line.strip()
print type(domain)
print "IDN:", domain.encode("idna")
print
Which gave me:
$ ./idn.py ./test
Traceback (most recent call last):
File "./idn.py", line 8, in <module>
for line in infile:
File "/usr/lib/python2.6/codecs.py", line 679, in next
return self.reader.next()
File "/usr/lib/python2.6/codecs.py", line 610, in next
line = self.readline()
File "/usr/lib/python2.6/codecs.py", line 525, in readline
data = self.read(readsize, firstline=True)
File "/usr/lib/python2.6/codecs.py", line 472, in read
newchars, decodedbytes = self.decode(data, self.errors)
UnicodeDecodeError: 'utf8' codec can't decode bytes in position 0-5: unsupported Unicode code range
Here is my test data file:
pfarmer.com
pfarmerü.com
I'm very aware of my need to understand unicode now.
Thanks,
Peter

you need to know in which encoding you file was saved. This would be something like 'utf-8' (which is NOT Unicode) or 'iso-8859-1' or 'cp1252' or alike.
Then you can do (assuming 'utf-8'):
infile = open(sys.argv[1])
for line in infile:
print line,
domain = line.strip().decode('utf-8')
print type(domain)
print "IDN:", domain.encode("idna")
print
Convert encoded strings to unicode with decode. Convert unicode to string with encode. If you try to encode something which is already encoded, python tries to decode first, with the default codec 'ascii' which fails for non-ASCII-values.

Your first example is fine, except that:
domain = unicode(line.strip())
you have to specify a particular encoding here: unicode(line.strip(), 'utf-8'). Otherwise you get the default encoding which for safety is 7-bit ASCII, hence the error. Alternatively you can spell it line.strip().decode('utf-8') as in knitti's example; there is no difference in behaviour between the two syntaxes.
However judging by the error “can't decode byte 0xfc”, I think you haven't actually saved your test file as UTF-8. Presumably this is why the second example, that also looks OK in principle, fails.
Instead it's ISO-8859-1 or the very similar Windows code page 1252. If it's come from a text editor on a Western Windows box it will certainly be the latter; Linux machines use UTF-8 by default instead nowadays. Either make sure to save your file as UTF-8, or read the file using the encoding 'cp1252' instead.