How to filter Unicode characters [duplicate] - python

I'm trying to get a Python 3 program to do some manipulations with a text file filled with information. However, when trying to read the file I get the following error:
Traceback (most recent call last):
File "SCRIPT LOCATION", line NUMBER, in <module>
text = file.read()
File "C:\Python31\lib\encodings\cp1252.py", line 23, in decode
return codecs.charmap_decode(input,self.errors,decoding_table)[0]
UnicodeDecodeError: 'charmap' codec can't decode byte 0x90 in position 2907500: character maps to `<undefined>`

The file in question is not using the CP1252 encoding. It's using another encoding. Which one you have to figure out yourself. Common ones are Latin-1 and UTF-8. Since 0x90 doesn't actually mean anything in Latin-1, UTF-8 (where 0x90 is a continuation byte) is more likely.
You specify the encoding when you open the file:
file = open(filename, encoding="utf8")

If file = open(filename, encoding="utf-8") doesn't work, try
file = open(filename, errors="ignore"), if you want to remove unneeded characters. (docs)

Alternatively, if you don't need to decode the file, such as uploading the file to a website, use:
open(filename, 'rb')
where r = reading, b = binary

As an extension to #LennartRegebro's answer:
If you can't tell what encoding your file uses and the solution above does not work (it's not utf8) and you found yourself merely guessing - there are online tools that you could use to identify what encoding that is. They aren't perfect but usually work just fine. After you figure out the encoding you should be able to use solution above.
EDIT: (Copied from comment)
A quite popular text editor Sublime Text has a command to display encoding if it has been set...
Go to View -> Show Console (or Ctrl+`)
Type into field at the bottom view.encoding() and hope for the best (I was unable to get anything but Undefined but maybe you will have better luck...)

TLDR: Try: file = open(filename, encoding='cp437')
Why? When one uses:
file = open(filename)
text = file.read()
Python assumes the file uses the same codepage as current environment (cp1252 in case of the opening post) and tries to decode it to its own default UTF-8. If the file contains characters of values not defined in this codepage (like 0x90) we get UnicodeDecodeError. Sometimes we don't know the encoding of the file, sometimes the file's encoding may be unhandled by Python (like e.g. cp790), sometimes the file can contain mixed encodings.
If such characters are unneeded, one may decide to replace them by question marks, with:
file = open(filename, errors='replace')
Another workaround is to use:
file = open(filename, errors='ignore')
The characters are then left intact, but other errors will be masked too.
A very good solution is to specify the encoding, yet not any encoding (like cp1252), but the one which has ALL characters defined (like cp437):
file = open(filename, encoding='cp437')
Codepage 437 is the original DOS encoding. All codes are defined, so there are no errors while reading the file, no errors are masked out, the characters are preserved (not quite left intact but still distinguishable).

Stop wasting your time, just add the following encoding="cp437" and errors='ignore' to your code in both read and write:
open('filename.csv', encoding="cp437", errors='ignore')
open(file_name, 'w', newline='', encoding="cp437", errors='ignore')
Godspeed

for me encoding with utf16 worked
file = open('filename.csv', encoding="utf16")

For those working in Anaconda in Windows, I had the same problem. Notepad++ help me to solve it.
Open the file in Notepad++. In the bottom right it will tell you the current file encoding.
In the top menu, next to "View" locate "Encoding". In "Encoding" go to "character sets" and there with patiente look for the enconding that you need. In my case the encoding "Windows-1252" was found under "Western European"

Before you apply the suggested solution, you can check what is the Unicode character that appeared in your file (and in the error log), in this case 0x90: https://unicodelookup.com/#0x90/1 (or directly at Unicode Consortium site http://www.unicode.org/charts/ by searching 0x0090)
and then consider removing it from the file.

def read_files(file_path):
with open(file_path, encoding='utf8') as f:
text = f.read()
return text
OR (AND)
def read_files(text, file_path):
with open(file_path, 'rb') as f:
f.write(text.encode('utf8', 'ignore'))

In the newer version of Python (starting with 3.7), you can add the interpreter option -Xutf8, which should fix your problem. If you use Pycharm, just got to Run > Edit configurations (in tab Configuration change value in field Interpreter options to -Xutf8).
Or, equivalently, you can just set the environmental variable PYTHONUTF8 to 1.

for me changing the Mysql character encoding the same as my code helped to sort out the solution. photo=open('pic3.png',encoding=latin1)

Related

Can't read a .csv with python: "UnicodeDecodeError: 'charmap' codec can't decode byte 0x81 in position..." [duplicate]

I'm trying to get a Python 3 program to do some manipulations with a text file filled with information. However, when trying to read the file I get the following error:
Traceback (most recent call last):
File "SCRIPT LOCATION", line NUMBER, in <module>
text = file.read()
File "C:\Python31\lib\encodings\cp1252.py", line 23, in decode
return codecs.charmap_decode(input,self.errors,decoding_table)[0]
UnicodeDecodeError: 'charmap' codec can't decode byte 0x90 in position 2907500: character maps to `<undefined>`
The file in question is not using the CP1252 encoding. It's using another encoding. Which one you have to figure out yourself. Common ones are Latin-1 and UTF-8. Since 0x90 doesn't actually mean anything in Latin-1, UTF-8 (where 0x90 is a continuation byte) is more likely.
You specify the encoding when you open the file:
file = open(filename, encoding="utf8")
If file = open(filename, encoding="utf-8") doesn't work, try
file = open(filename, errors="ignore"), if you want to remove unneeded characters. (docs)
Alternatively, if you don't need to decode the file, such as uploading the file to a website, use:
open(filename, 'rb')
where r = reading, b = binary
As an extension to #LennartRegebro's answer:
If you can't tell what encoding your file uses and the solution above does not work (it's not utf8) and you found yourself merely guessing - there are online tools that you could use to identify what encoding that is. They aren't perfect but usually work just fine. After you figure out the encoding you should be able to use solution above.
EDIT: (Copied from comment)
A quite popular text editor Sublime Text has a command to display encoding if it has been set...
Go to View -> Show Console (or Ctrl+`)
Type into field at the bottom view.encoding() and hope for the best (I was unable to get anything but Undefined but maybe you will have better luck...)
TLDR: Try: file = open(filename, encoding='cp437')
Why? When one uses:
file = open(filename)
text = file.read()
Python assumes the file uses the same codepage as current environment (cp1252 in case of the opening post) and tries to decode it to its own default UTF-8. If the file contains characters of values not defined in this codepage (like 0x90) we get UnicodeDecodeError. Sometimes we don't know the encoding of the file, sometimes the file's encoding may be unhandled by Python (like e.g. cp790), sometimes the file can contain mixed encodings.
If such characters are unneeded, one may decide to replace them by question marks, with:
file = open(filename, errors='replace')
Another workaround is to use:
file = open(filename, errors='ignore')
The characters are then left intact, but other errors will be masked too.
A very good solution is to specify the encoding, yet not any encoding (like cp1252), but the one which has ALL characters defined (like cp437):
file = open(filename, encoding='cp437')
Codepage 437 is the original DOS encoding. All codes are defined, so there are no errors while reading the file, no errors are masked out, the characters are preserved (not quite left intact but still distinguishable).
Stop wasting your time, just add the following encoding="cp437" and errors='ignore' to your code in both read and write:
open('filename.csv', encoding="cp437", errors='ignore')
open(file_name, 'w', newline='', encoding="cp437", errors='ignore')
Godspeed
for me encoding with utf16 worked
file = open('filename.csv', encoding="utf16")
For those working in Anaconda in Windows, I had the same problem. Notepad++ help me to solve it.
Open the file in Notepad++. In the bottom right it will tell you the current file encoding.
In the top menu, next to "View" locate "Encoding". In "Encoding" go to "character sets" and there with patiente look for the enconding that you need. In my case the encoding "Windows-1252" was found under "Western European"
Before you apply the suggested solution, you can check what is the Unicode character that appeared in your file (and in the error log), in this case 0x90: https://unicodelookup.com/#0x90/1 (or directly at Unicode Consortium site http://www.unicode.org/charts/ by searching 0x0090)
and then consider removing it from the file.
def read_files(file_path):
with open(file_path, encoding='utf8') as f:
text = f.read()
return text
OR (AND)
def read_files(text, file_path):
with open(file_path, 'rb') as f:
f.write(text.encode('utf8', 'ignore'))
In the newer version of Python (starting with 3.7), you can add the interpreter option -Xutf8, which should fix your problem. If you use Pycharm, just got to Run > Edit configurations (in tab Configuration change value in field Interpreter options to -Xutf8).
Or, equivalently, you can just set the environmental variable PYTHONUTF8 to 1.
for me changing the Mysql character encoding the same as my code helped to sort out the solution. photo=open('pic3.png',encoding=latin1)

Reading Hong Kong Supplementary Character Set in python 3

I have a hkscs dataset that I am trying to read in python 3. Below code
encoding = 'big5hkscs'
lines = []
num_errors = 0
for line in open('file.txt'):
try:
lines.append(line.decode(encoding))
except UnicodeDecodeError as e:
num_errors += 1
It throws me error UnicodeDecodeError: 'utf-8' codec can't decode byte 0xae in position 0: invalid start byte. Seems like there is a non utf-8 character in the dataset that the code is not able to decode.
I tried adding errors = ignore in this line
lines.append(line.decode(encoding, errors='ignore'))
But that does not solve the problem.
Can anyone please suggest?
If a text file contains text encoded with an encoding that is not the default encoding, the encoding must be specified when opening the file to avoid decoding errors:
encoding = 'big5hkscs'
path = 'file.txt'
with open(path, 'r', encoding=encoding,) as f:
for line in f:
# do something with line
Alternatively, the file may be opened in binary mode, and text decoded afterwards:
encoding = 'big5hkscs'
path = 'file.txt'
with open(path, 'rb') as f:
for line in f:
decoded = line.decode(encoding)
# do something with decoded text
In the question, the file is opened without specifying an encoding, so its contents are automatically decoded with the default encoding - apparently UTF-8 in the is case.
Looks like if I do NOT add the except clause except UnicodeDecodeError as e, it works fine
encoding = 'big5hkscs'
lines = []
path = 'file.txt'
with open(path, encoding=encoding, errors='ignore') as f:
for line in f:
line = '\t' + line
lines.append(line)
The answer of snakecharmerb is correct, but possibly you need an explanation.
You didn't write it in the original question, but I assume you have the error on the for line. In this line you are decoding the file from UTF-8 (probably the default on your environment, so not on Windows), but later you are trying to decode it again. So the error is not about decoding big5hkscs, but about opening the file as text.
As in the good answer of snakecharmerb (second part), you should open the file as binary, so without decoding texts, and then you can decode the text with line.decode(encoding). Note: I'm not sure you can read lines on a binary file. In this manner you can still catch the errors, e.g. to write a message. Else the normal way is to decode at open() time, but then you loose the ability to fall back and to get users better error message (e.g. line number).

how to read both ANSI and Unicode txt files in Python?

I'm new to python and face a strange problem:
When I have 50 txt files in a directory, I want to read each .txt file and save its content in a unique variable like:
**file = open(fcf[i], 'r')
text[i] = file.read()**
When I only read one file, it's ok:
count = 0
for file_flag in fcf:
if file_flag == 'feature.txt':
file = open(fcf[count], 'r')
features = file.read().split() # a list, word by word
count = count+1
However, to read txt files in a loop, it's wrong:
Below is my code and a very strange error comes up,
**text = np.zeros((np.shape(fcf)[0],1))
for flag in range(np.shape(fcf)[0]):
file = open(fcf[flag], 'r')
text = file.read() # string
file.close()**
---------------------------------------------------------------------------
UnicodeDecodeError Traceback (most recent call last)
<ipython-input-41-7e544d88ee9d> in <module>()
2 for flag in range(np.shape(fcf)[0]):
3 file = open(fcf[flag], 'r')
----> 4 text = file.read() # string
5 file.close()
**UnicodeDecodeError: 'gbk' codec can't decode byte 0x94 in position 418: illegal multibyte sequence**
Update:
in a loop form:
file = open(fcf[flag], 'r', encoding='UTF-8')
the error also occurs:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x94 in position 418: invalid start byte
Could anyone help me? Thank you very much!
Update2:
It seems that in these .txt files, most of them are in Unicode, which is durable for python. I find that, in notepad, there are 2 .txt file in ANSI encoding, which leads to this problem.
How could I read both ANSI and Unicode together in python?
Update3:
Thanks everyone. This problem is fixed.
There are 2 reasons for this problem:
some ANSI txt files are in overall UTF8 files.
some weird matches appears on ANSI encoding:
didn’t - didn抰
weren’t - weren抰, etc. (‘n -> 抰)
("Well - 揥ell)
although my PC is in English language totally, this problem still happens for ANSI txt. (manually modification is needed since notepad only change the encoding, not the above weird character...)
Hope it helps for other people facing the similar problem. Thx
You open your file in default text mode. When reading it, Python tries to decode it, using the default encoding for your platform, which seems to be 'gbk'.
Apparently, the file you're trying to read uses another encoding, which causes this error.
You have to indicate the encoding to use in open. If it is 'UTF-8', for example:
file = open(fcf[flag], 'r', encoding='UTF-8')
If your file uses a different encoding, you must figure it out first, I don't know what is common in your part of the world. You can have a look at the list of standard encodings.
For chinese, the listed encodings are 'gb2312', 'gb18030', 'hz', you could try with these ones.

Error UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 0: invalid start byte

https://github.com/affinelayer/pix2pix-tensorflow/tree/master/tools
An error occurred when compiling "process.py" on the above site.
python tools/process.py --input_dir data -- operation resize --outp
ut_dir data2/resize
data/0.jpg -> data2/resize/0.png
Traceback (most recent call last):
File "tools/process.py", line 235, in <module>
main()
File "tools/process.py", line 167, in main
src = load(src_path)
File "tools/process.py", line 113, in load
contents = open(path).read()
File"/home/user/anaconda3/envs/tensorflow_2/lib/python3.5/codecs.py", line 321, in decode
(result, consumed) = self._buffer_decode(data, self.errors, final)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 0: invalid start byte
What is the cause of the error?
Python's version is 3.5.2.
Python tries to convert a byte-array (a bytes which it assumes to be a utf-8-encoded string) to a unicode string (str). This process of course is a decoding according to utf-8 rules. When it tries this, it encounters a byte sequence which is not allowed in utf-8-encoded strings (namely this 0xff at position 0).
Since you did not provide any code we could look at, we only could guess on the rest.
From the stack trace we can assume that the triggering action was the reading from a file (contents = open(path).read()). I propose to recode this in a fashion like this:
with open(path, 'rb') as f:
contents = f.read()
That b in the mode specifier in the open() states that the file shall be treated as binary, so contents will remain a bytes. No decoding attempt will happen this way.
Use this solution it will strip out (ignore) the characters and return the string without them. Only use this if your need is to strip them not convert them.
with open(path, encoding="utf8", errors='ignore') as f:
Using errors='ignore'
You'll just lose some characters. but if your don't care about them as they seem to be extra characters originating from a the bad formatting and programming of the clients connecting to my socket server.
Then its a easy direct solution.
reference
Use encoding format ISO-8859-1 to solve the issue.
Had an issue similar to this, Ended up using UTF-16 to decode. my code is below.
with open(path_to_file,'rb') as f:
contents = f.read()
contents = contents.rstrip("\n").decode("utf-16")
contents = contents.split("\r\n")
this would take the file contents as an import, but it would return the code in UTF format. from there it would be decoded and seperated by lines.
I've come across this thread when suffering the same error, after doing some research I can confirm, this is an error that happens when you try to decode a UTF-16 file with UTF-8.
With UTF-16 the first characther (2 bytes in UTF-16) is a Byte Order Mark (BOM), which is used as a decoding hint and doesn't appear as a character in the decoded string. This means the first byte will be either FE or FF and the second, the other.
Heavily edited after I found out the real answer
It simply means that one chose the wrong encoding to read the file.
On Mac, use file -I file.txt to find the correct encoding. On Linux, use file -i file.txt.
I had a similar issue with PNG files. and I tried the solutions above without success.
this one worked for me in python 3.8
with open(path, "rb") as f:
use only
base64.b64decode(a)
instead of
base64.b64decode(a).decode('utf-8')
This is due to the different encoding method when read the file. In python, it defaultly
encode the data with unicode. However, it may not works in various platforms.
I propose an encoding method which can help you solve this if 'utf-8' not works.
with open(path, newline='', encoding='cp1252') as csvfile:
reader = csv.reader(csvfile)
It should works if you change the encoding method here. Also, you can find other encoding method here standard-encodings , if above doesn't work for you.
Those getting similar errors while handling Pandas for data frames use the following solution.
example solution.
df = pd.read_csv("File path", encoding='cp1252')
I had this UnicodeDecodeError while trying to read a '.csv' file using pandas.read_csv(). In my case, I could not manage to overcome this issue using other encoder types. But instead of using
pd.read_csv(filename, delimiter=';')
I used:
pd.read_csv(open(filename, 'r'), delimiter=';')
which just seems working fine for me.
Note that: In open() function, use 'r' instead of 'rb'. Because 'rb' returns bytes object that causes to happen this decoder error in the first place, that is the same problem in the read_csv(). But 'r' returns str which is needed since our data is in .csv, and using the default encoding='utf-8' parameter, we can easily parse the data using read_csv() function.
if you are receiving data from a serial port, make sure you are using the right baudrate (and the other configs ) : decoding using (utf-8) but the wrong config will generate the same error
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 0: invalid start byte
to check your serial port config on linux use : stty -F /dev/ttyUSBX -a
I had a similar issue and searched all the internet for this problem
if you have this problem just copy your HTML code in a new HTML file and use the normal <meta charset="UTF-8">
and it will work....
just create a new HTML file in the same location and use a different name
Check the path of the file to be read. My code kept on giving me errors until I changed the path name to present working directory. The error was:
newchars, decodedbytes = self.decode(data, self.errors)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 0: invalid start byte
If you are on a mac check if you for a hidden file, .DS_Store. After removing the file my program worked.
I had a similar problem.
Solved it by:
import io
with io.open(filename, 'r', encoding='utf-8') as fn:
lines = fn.readlines()
However, I had another problem. Some html files (in my case) were not utf-8, so I received a similar error. When I excluded those html files, everything worked smoothly.
So, except from fixing the code, check also the files you are reading from, maybe there is an incompatibility there indeed.
You have to use the encoding as latin1 to read this file as there are some special character in this file, use the below code snippet to read the file.
The problem here is the encoding type. When Python can't convert the data to be read, it gives an error.
You can you latin1 or other encoding values.
I say try and test to find the right one for your dataset.
I have the same issue when processing a file generated from Linux. It turns out it was related with files containing question marks..
Following code worked in my case:
df = pd.read_csv(filename,sep = '\t', encoding='cp1252')
If possible, open the file in a text editor and try to change the encoding to UTF-8. Otherwise do it programatically at the OS level.

Why does opening a file in two different encodings work as expected?

Quoting from here,
The default encoding is platform-dependent, so this code might work on your computer (if your default encoding is utf-8), but then it will fail when you distribute it to someone else (whose default encoding is different, like CP-1252).
Code mentioned in the above quote:
fp = open('text.txt') # Assuming file exists
a_string = file.read()
I have created a file named text.txt (with random contents) in the current directory and the encoding of it is "ANSI 1252" (checked using notepad++). I have checked the default encoding of my system(windows) using
import locale
print(locale.getpreferredencoding())
which gives the output
cp1252
The code to read the file (which I've provided just below the quote) works as expected. It works even when I used
fp = open('text.txt', encoding='utf-8') # or `fp = open('text.txt', encoding='cp1252')`
How does the above code work for two different encodings? Shouldn't it give a UnicodeDecodeError or something like that?
Decode would only fail if the input contains characters outside the encoding mapping. If your file is purely ASCII, it will be read in exactly the same in both cases.
Looking here, the mappings are the same.
And from what I understand, the unicode standard was designed to be backwards compatible with ascii.

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