Here's a problem I am facing with encoding and decoding texts.
I am trying to write a code that finds a 'string' or a 'byte' in a file, and return the path of the file.
Currently, since the files I am opening have encoding of 'windows-1252' or 'cp-1252', so I have been trying to:
1. encode my string into a byte corresponding to the encoding of the file
2. match the file and get the path of that file
I have a file, say 'f', that has the encoding of 'windows-1252' or 'cp-1252'. It includes a text that is in Chinese: '[跑Online農場]'
with open(os.path.join(root, filename), mode='rb') as f:
text = f.read()
print(encoding(text)) # encoding() is a separate function that I wrote that returns the encoding of the file
print(text)
Windows-1252
b'\x00StaticText\x00\x00\x12\x00[\xb6]Online\xb9A\xb3\xf5]\x00\x01\x00\x ...
As you may see, the 'binary' texts for [跑Online農場] is [\xb6]Online\xb9A\xb3\xf5]
However, the funny thing is that if I literally convert the string into bytes, I get:
enter_text = '[跑Online農場]'
print(bytes(enter_text, 'cp1252'))
UnicodeEncodeError: 'charmap' codec can't encode character '\u8dd1' in position 1: character maps to <undefined>
On the other hand, opening the file using
with open(os.path.join(root, filename), mode='r', encoding='cp-1252') as f ...
I get:
StaticText [¶]Online¹A³õ] €?‹ Œ î...
which I am not sure how I would 'translate' '[跑Online農場]' into '[¶]Online¹A³õ]'. Answer to this may also solve the problem
What should I do to correctly 'encode' the Chinese/Foreign characters so that it matches the 'rb' bytes that the Python returns?
Thank you!
Your encoding function is wrong: the codec of the file is probably CP950, but certainly not CP1252.
Note: guessing the encoding of a given byte string is always approximate.
There's no safe way of determining the encoding for sure.
If you have a byte string like
b'[\xb6]Online\xb9A\xb3\xf5]'
and you know it must translate (be decoded) into
'[跑Online農場]'
then what you can is trial and error with a few codecs.
I did this with the list of codecs supported by Python, searching for codecs for Chinese.
When using CP-1252 (the Windows version of Latin-1), as you did, you get mojibake:
>>> b'[\xb6]Online\xb9A\xb3\xf5]'.decode('cp1252')
'[¶]Online¹A³õ]'
When using CP-950 (the Windows codepage for Traditional Chinese), you get the expected output:
>>> b'[\xb6]Online\xb9A\xb3\xf5]'.decode('cp950')
'[跑Online農場]'
So: use CP-950 for reading the file.
Related
From a client I am getting a pdf file, which is encoded in cp 1252 and for transfer is also encoded in base 64. Till now a shell program returns the file into the original form through this code line:
output= [System.Text.Encoding]::GetEncoding(1252).GetString([System.Convert]::FromBase64String(input))
and this works.
Now I am implementing a python version, to supersede this implementation. This looks generally like this:
enc_file = read_from_txt.open_file(location_of_file)
plain_file= base64.b64decode(enc_file)
with open('filename', 'w') as writer:
writer.write(plain_file.decode('cp1252'))
where read_from_txt.open_file just does this:
with open(file_location, 'rb') as fileReader:
read = fileReader.read()
return read
But for some reason, I am getting an error in the plain_file.decode('cp1252'), where it can not decode a line in the file. From what I am understanding though, the python program should do exactly the same, as the powershell does.
Concrete error is:
UnicodeDecodeError: 'charmap' codec can't decode byte 0x81 in position 188: character maps to undefined
Any help is appreciated.
I am trying to create a CSV file that contains Arabic tweets collected using tweepy for a project I am doing. All is fine gathering the data, however, when i am writing to the CSV file all Arabic results are escaped with \xXXXX sequences
as follows:
b'#\xd8\xa7\xd9\x84\xd9\x8a\xd9\x88\xd9\x85_\xd8\xa7\xd9\x84\xd8\xb9\xd8\xa7\xd9\x84\xd9\x85\xd9\x8a_\xd9\x84\xd9\x84\xd8\xa7\xd8\xb9\xd8\xa7\xd9\x82\xd9\x87_2017 \xd8\xa7\xd9\x84\xd8\xa5\xd8\xb9\xd8\xa7\xd9\x82\xd8\xa9 \xd8\xa7\xd9\x84\xd8\xad\xd9\x82\xd9\x8a\xd9\x82\xd9\x8a\xd8\xa9 \xd8\xa7\xd8\xb9\xd8\xa7\xd9\x82\xd8\xa9 \xd8\xa7\xd9\x84\xd9\x81\xd9\x83\xd8\xb1 \xd9\x88\xd9\x84\xd9\x8a\xd8\xb3\xd8\xaa \xd8\xa7\xd8\xb9\xd8\xa7\xd9\x82\xd8\xa9
I looked at many previously asked questions and all I could find was suggestions for python 2 or answers similar to the one I am writing. When I was creating JSON files instead I was using ensure_ascii=False but I couldn't find anything similar for CSV. Below is my code:
with codecs.open('tweets.csv', 'a', encoding='utf-8') as file:
fieldnames = ['tweet', 'country']
writer = csv.DictWriter(file, fieldnames=fieldnames)
data = {'tweet': status.text, 'country': status.place.full_name}
writer.writerow(data)
I tried adding .encoding='utf-8' to status.text and status.place as well but that also didn't work. Any suggestions?
You have to make sure the Arabic string you have is decoded into UTF-8 before you write it. Assuming status.text is of type bytes you should type text=status.text.decode('utf-8'). (Maybe you have to do this for status.place.full_name too.) But if it's of type str then it won't have an decode() method. To avoid escape sequences in your file, a str object should be written anyway.
If you try to specify the encoding of a bytes object (like the one you presumably have) as 'utf-8' that won't work because the text is already in UTF-8 bytes. So in order to get UTF-8 characters you must call decode() on the bytes object. That way it writes the UTF-8 characters and not the UTF-8 bytes.
I am a newbie in Python3.
I have a question in writing a string into a file.
The below string is what I tried to write into a file.
ÀH \x10\x08\x81\x00 (in hex, c04820108810)
When I checked the file using xxd command, I could check there is a difference between the string and the file.
00000000: c380 4820 1008 c281 00 ..H .....
This is code I wrote.
s = 'ÀH \x10\x08\x81\x00'
with open('test', 'w') as f:
f.write(s)
The question is how can I write this string into file in its entirety.
It seems that you want to write binary data. In that case, you should use the bytes type instead of str as this gives you full control over the binary content of the sequence.
When dealing with strings, you have to take into account that Python will internally handle everything as UTF-8, so by the time you enter something like À, the file encoding will decide on what is actually entered. You can always encode() a string to look at its bytes:
>>> 'ÀH \x10\x08\x81\x00'.encode()
b'\xc3\x80H \x10\x08\xc2\x81\x00'
You can convert this to hex using the binascii module for a more readable hex string of those bytes:
>>> binascii.hexlify('ÀH \x10\x08\x81\x00'.encode())
b'c38048201008c28100'
As you can see, this is the same that was written to your file. So Python already does the correct thing. It’s just that the input is not what you want it to be.
So instead, use a bytes string and write to the file in binary mode:
# use a bytes string
s = b'\xc0\x48\x20\x10\x88\x10'
# open the file in binary mode
with open('test', 'bw') as f:
f.write(s)
Btw. if you look at the encoded string from the beginning, you can already see that you have a different encoding in mind than Python when you entered that string. You expected À to be 0xc0 in binary which is somewhat correct since that its Latin-1 representation. But when you lookup its other representations, you can see that in UTF-8, which is what Python uses by default, it is 0xc380 instead—which is again the value we got when encoding it in Python.
You have to setup coding style to utf-8 and also use raw strings because you have \ escape characters. So add coding style and put r before your string to make it raw.
# -*- coding: utf-8 -*-
s = r'ÀH \x10\x08\x81\x00'
with open('test.txt', 'w') as f:
f.write(s)
The problem is that for some archives or files up-loaded to the python application, ZipFile's namelist() returns badly decoded strings.
from zip import ZipFile
for name in ZipFile('zipfile.zip').namelist():
print('Listing zip files: %s' % name)
How to fix that code so i always decode file names in unicode (so Chineeze, Russian and other languages supported)?
I've seen some samples for Python 2, but since string's nature is changed in python3, i have no clue how to re-encode it, or apply chardet on it.
How to fix that code so i always decode file names in unicode (so Chineeze, Russian and other languages supported)?
Automatically? You can't. Filenames in a basic ZIP file are strings of bytes with no attached encoding information, so unless you know what the encoding was on the machine that created the ZIP you can't reliably get a human-readable filename back out.
There is an extension to the flags on modern ZIP files to tell you that the filename is UTF-8. Unfortunately files you receive from Windows users typically don't have it, so you'll left guessing with inherently unreliable methods like chardet.
I've seen some samples for Python 2, but since string's nature is changed in python3, i have no clue how to re-encode it, or apply chardet on it.
Python 2 would just give you raw bytes back. In Python 3 the new behaviour is:
if the UTF-8 flag is set, it decodes the filenames using UTF-8 and you get the correct string value back
otherwise, it decodes the filenames using DOS code page 437, which is pretty unlikely to be what was intended. However you can re-encode the string back to the original bytes, and then try to decode again using the code page you actually want, eg name.encode('cp437').decode('cp1252').
Unfortunately (again, because the unfortunatelies never end where ZIP is concerned), ZipFile does this decoding silently without telling you what it did. So if you want to switch and only do the transcode step when the filename is suspect, you have to duplicate the logic for sniffing whether the UTF-8 flag was set:
ZIP_FILENAME_UTF8_FLAG = 0x800
for info in ZipFile('zipfile.zip').filelist():
filename = info.filename
if info.flag_bits & ZIP_FILENAME_UTF8_FLAG == 0:
filename_bytes = filename.encode('437')
guessed_encoding = chardet.detect(filename_bytes)['encoding'] or 'cp1252'
filename = filename_bytes.decode(guessed_encoding, 'replace')
...
Here's the code that decodes filenames in zipfile.py according to the zip spec that supports only cp437 and utf-8 character encodings:
if flags & 0x800:
# UTF-8 file names extension
filename = filename.decode('utf-8')
else:
# Historical ZIP filename encoding
filename = filename.decode('cp437')
As you can see, if 0x800 flag is not set i.e., if utf-8 is not used in your input zipfile.zip then cp437 is used and therefore the result for "Chineeze, Russian and other languages" is likely to be incorrect.
In practice, ANSI or OEM Windows codepages may be used instead of cp437.
If you know the actual character encoding e.g., cp866 (OEM (console) codepage) may be used on Russian Windows then you could reencode filenames to get the original filenames:
filename = corrupted_filename.encode('cp437').decode('cp866')
The best option is to create the zip archive using utf-8 so that you can support multiple languages in the same archive:
c:\> 7z.exe a -tzip -mcu archive.zip <files>..
or
$ python -mzipfile -c archive.zip <files>..`
Got the same problem, but with defined language (Russian).
Most simple solution is just to convert it with this utility: https://github.com/vlm/zip-fix-filename-encoding
For me it works on 98% of archives (failed to run on 317 files from corpus of 11388)
More complex solution: use python module chardet with zipfile. But it depends on python version (2 or 3) you use - it has some differences on zipfile. For python 3 I wrote a code:
import chardet
original_name = name
try:
name = name.encode('cp437')
except UnicodeEncodeError:
name = name.encode('utf8')
encoding = chardet.detect(name)['encoding']
name = name.decode(encoding)
This code try to work with old style zips (having encoding CP437 and just has it broken), and if fails, it seems that zip archive is new style (UTF-8). After determining proper encoding, you can extract files by code like:
from shutil import copyfileobj
fp = archive.open(original_name)
fp_out = open(name, 'wb')
copyfileobj(fp, fp_out)
In my case, this resolved last 2% of failed files.
I still do not understand completely how python's unicode and str types work. Note: I am working in Python 2, as far as I know Python 3 has a completely different approach to the same issue.
What I know:
str is an older beast that saves strings encoded by one of the way too many encodings that history has forced us to work with.
unicode is an more standardised way of representing strings using a huge table of all possible characters, emojis, little pictures of dog poop and so on.
The decode function transforms strings to unicode, encode does the other way around.
If I, in python's shell, simply say:
>>> my_string = "some string"
then my_string is a str variable encoded in ascii (and, because ascii is a subset of utf-8, it is also encoded in utf-8).
Therefore, for example, I can convert this into a unicode variable by saying one of the lines:
>>> my_string.decode('ascii')
u'some string'
>>> my_string.decode('utf-8')
u'some string'
What I don't know:
How does Python handle non-ascii strings that are passed in the shell, and, knowing this, what is the correct way of saving the word "kožušček"?
For example, I can say
>>> s1 = 'kožušček'
In which case s1 becomes a str instance that I am unable to convert into unicode:
>>> s1='kožušček'
>>> s1
'ko\x9eu\x9a\xe8ek'
>>> print s1
kožušček
>>> s1.decode('ascii')
Traceback (most recent call last):
File "<pyshell#23>", line 1, in <module>
s1.decode('ascii')
UnicodeDecodeError: 'ascii' codec can't decode byte 0x9e in position 2: ordinal not in range(128)
Now, naturally I can't decode the string with ascii, but what encoding should I then use? After all, my sys.getdefaultencoding() returns ascii! Which encoding did Python use to encode s1 when fed the line s1=kožušček?
Another thought I had was to say
>>> s2 = u'kožušček'
But then, when I printed s2, I got
>>> print s2
kouèek
which means that Python lost a whole letter. Can someone explain this to me?
str objects contain bytes. What those bytes represent Python doesn't dictate. If you produced ASCII-compatible bytes, you can decode them as ASCII. If they contain bytes representing UTF-8 data they can be decoded as such. If they contain bytes representing an image, then you can decode that information and display an image somewhere. When you use repr() on a str object Python will leave any bytes that are ASCII printable as such, the rest are converted to escape sequences; this keeps debugging such information practical even in ASCII-only environments.
Your terminal or console in which you are running the interactive interpreter writes bytes to the stdin stream that Python reads from when you type. Those bytes are encoded according to the configuration of that terminal or console.
In your case, your console encoded the input you typed to a Windows codepage, most likely. You'll need to figure out the exact codepage and use that codec to decode the bytes. Codepage 1252 seems to fit:
>>> print 'ko\x9eu\x9a\xe8ek'.decode('cp1252')
kožušèek
When you print those same bytes, your console is reading those bytes and interpreting them in the same codec it is already configured with.
Python can tell you what codec it thinks your console is set to; it tries to detect this information for Unicode literals, where the input has to be decoded for you. It uses the locale.getpreferredencoding() function to determine this, and the sys.stdin and sys.stdout objects have an encoding attribute; mine is set to UTF-8:
>>> import sys
>>> sys.stdin.encoding
'UTF-8'
>>> import locale
>>> locale.getpreferredencoding()
'UTF-8'
>>> 'kožušèek'
'ko\xc5\xbeu\xc5\xa1\xc3\xa8ek'
>>> u'kožušèek'
u'ko\u017eu\u0161\xe8ek'
>>> print u'kožušèek'
kožušèek
Because my terminal has been configured for UTF-8 and Python has detected this, using a Unicode literal u'...' works. The data is automatically decoded by Python.
Why exactly your console lost a whole letter I don't know; I'd have to have access to your console and do some more experiments, see the output of print repr(s2), and test all bytes between 0x00 and 0xFF to see if this is on the input or output side of the console.
I recommend you read up on Python and Unicode:
Pragmatic Unicode by Ned Batchelder
The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) by Joel Spolsky
The Python Unicode HOWTO
Your system does not necessarily use the sys.getdefaultencoding() encoding; it is merely the default used when you convert without telling it the encoding, as in:
>>> sys.getdefaultencoding()
'ascii'
>>> unicode(s1)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc5 in position 2: ordinal not in range(128)
Python's idea of your system locale is in the locale module:
>>> import locale
>>> locale.getdefaultlocale()
('en_US', 'UTF-8')
>>> locale.getpreferredencoding()
'UTF-8'
And using this we can decode the string:
>>> u1=s1.decode(locale.getdefaultlocale()[1])
>>> u1
u'ko\u017eu\u0161\u010dek'
>>> print u1
kožušček
There's a chance the locale has not been set up, as is the case for the 'C' locale. That may cause the reported encoding to be None even though the default is 'ascii'. Normally figuring this out is the job of setlocale, which getpreferredencoding will automatically call. I would suggest calling it once in your program startup and saving the value returned for all further use. The encoding used for filenames may also be yet another case, reported in sys.getfilesystemencoding().
The Python-internal default encoding is set up by the site module, which contains:
def setencoding():
"""Set the string encoding used by the Unicode implementation. The
default is 'ascii', but if you're willing to experiment, you can
change this."""
encoding = "ascii" # Default value set by _PyUnicode_Init()
if 0:
# Enable to support locale aware default string encodings.
import locale
loc = locale.getdefaultlocale()
if loc[1]:
encoding = loc[1]
if 0:
# Enable to switch off string to Unicode coercion and implicit
# Unicode to string conversion.
encoding = "undefined"
if encoding != "ascii":
# On Non-Unicode builds this will raise an AttributeError...
sys.setdefaultencoding(encoding) # Needs Python Unicode build !
So if you want it set by default in every run of Python, you can change that first if 0 to if 1.