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Best way to remove '\xad' in Python?

I'm trying to build a corpus from the .txt file found at this link.
I believe the instances of \xad are supposedly 'soft-hyphens', but do not appear to be read correctly under UTF-8 encoding. I've tried encoding the .txt file as iso8859-15, using the code:
with open('Harry Potter 3 - The Prisoner Of Azkaban.txt', 'r',
encoding='iso8859-15') as myfile:
data=myfile.read().replace('\n', '')
data2 = data.split(' ')
This returns an array of 'words', but '\xad' remains attached to many entries in data2. I've tried
data_clean = data.replace('\\xad', '')
and
data_clean = data.replace('\\xad|\\xad\\xad','')
but this doesn't seem to remove the instances of '\xad'. Has anyone ran into a similar problem before? Ideally I'd like to encode this data as UTF-8 to avail of the nltk library, but it won't read the file with UTF-8 encoding as I get the following error:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xad in position 471: invalid start byte
Any help would be greatly appreciated!
Additional context: This is a recreational project with the aim of being able to generate stories based on the txt file. Everything I've generated thus far has been permeated with '\xad', which ruins the fun!

Your file almost certainly has actual U+00AD soft-hyphen characters in it.
These are characters that mark places where a word could be split when fitting lines to a page. The idea is that the soft hyphen is invisible if the word doesn't need to be split, but printed the same as a U+2010 normal hyphen if it does.
Since you don't care about rendering this text in a book with nicely flowing text, you're never going to hyphenate anything, so you just want to remove these characters.
The way to do this is not to fiddle with the encoding. Just remove them from the Unicode text, using whichever of these you find most readable:
data = data.replace('\xad', '')
data = data.replace('\u00ad', '')
data = data.replace('\N{SOFT HYPHEN}', '')
Notice the single backslash. We're not replacing a literal backslash, x, a, d, we're replacing a literal soft-hyphen character, that is, the character whose code point is hex 0xad.
You can either do this to the whole file before splitting into words, or do it once per word after splitting.
Meanwhile, you seem to be confused about what encodings are and what to do with them:
I've tried encoding the .txt file as iso8859-15
No, you've tried decoding the file as ISO-8859-15. It's not clear why you tried ISO-8859-15 in the first place. But, since the ISO-8859-15 encoding for the character '\xad' is the byte b'\xad', maybe that's correct.
Ideally I'd like to encode this data as UTF-8 to avail of the nltk library
But NLTK doesn't want UTF-8 bytes, it wants Unicode strings. You don't need to encode it for that.
Plus, you're not trying to encode your Unicode text to UTF-8, you're trying to decode your bytes from UTF-8. If that's not what those bytes are… if you're lucky, you'll get an error like this one; if not, you'll get mojibake that you don't notice until you've screwed up a 500GB corpus and thrown away the original data.1
1. UTF-8 is specifically designed so you'll get early errors whenever possible. In this case, reading ISO-8859-15 text with soft hyphens as if it were UTF-8 raises exactly the error you're seeing, but reading UTF-8 text with soft hyphens as if it were ISO-8859-15 will silently succeed, but with an extra 'Â' character before each soft hyphen. The error is usually more helpful.

Running Python 2.7 Code With Unicode Characters in Source

I want to run a Python source file that contains unicode (utf-8) characters in the source. I am aware of the fact that this can be done by adding the comment # -*- coding: utf-8 -*- in the beginning. However, I wish to do it without using this method.
One way I could think of was writing the unicode strings in escaped form. For example,
Edit: Updated Source. Added Unicode comments.
# Printing naïve and 男孩
def fxn():
print 'naïve'
print '男孩'
fxn()
becomes
# Printing na\xc3\xafve and \xe7\x94\xb7\xe5\xad\xa9
def fxn():
print 'na\xc3\xafve'
print '\xe7\x94\xb7\xe5\xad\xa9'
fxn()
I have two questions regarding the above method.
How do I convert the first code snippet, using Python, into its equivalent that
follows it? That is, only unicode sequences should be written in
escaped form.
Is the method foolproof considering only unicode (utf-8) characters are used? Is there something that can go wrong?

Your idea is generally sound but will break in Python 3 and will cause a headache when you manipulating and writing your strings in Python 2.
It's a good idea to use Unicode strings, not regular strings when dealing with non-ASCII.
Instead, you can encode your characters as Unicode (not UTF-8) escape sequences in Unicode strings.
u'na\xefve'
u'\u7537\u5b69'
note the u prefix
Your code is now encoding agnostic.

If you only use byte strings, and save your source file encoded as UTF-8, your byte strings will contain UTF-8-encoded data. No need for the coding statement (although REALLY strange that you don't want to use it...it's just a comment). The coding statement let's Python know the encoding of the source file, so it can decode Unicode strings correctly (u'xxxxx'). If you have no Unicode strings, it doesn't matter.
For your questions, no need to convert to escape codes. If you encode the file as UTF-8, you can use the more readable characters in your byte strings.
FYI, that won't work for Python 3, because byte strings cannot contain non-ASCII in that version.
That said, here's some code that will convert your example as requested. It reads the source assuming it is encoded in UTF-8, then uses a regular expression to locate all non-ASCII characters. It passes them through a conversion function to generate the replacement. This should be safe, since non-ASCII can only be used in string literals and constants in Python 2. Python 3, however, allows non-ASCII in variable names so this wouldn't work there.
import io
import re
def escape(m):
char = m.group(0).encode('utf8')
return ''.join(r'\x{:02x}'.format(ord(b)) for b in char)
with io.open('sample.py',encoding='utf8') as f:
content = f.read()
new_content = re.sub(r'[^\x00-\x7f]',escape,content)
with io.open('sample_new.py','w',encoding='utf8') as f:
f.write(new_content)
Result:
# Printing na\xc3\xafve and \xe7\x94\xb7\xe5\xad\xa9
def fxn():
print 'na\xc3\xafve'
print '\xe7\x94\xb7\xe5\xad\xa9'
fxn()

question 1:
try to use:
print u'naïve'
print u'长者'
question 2:
If you type the sentences by keyboard and Chinese input software, everything should be OK. But if you copy and paste sentence from some web pages, you should consider other encode format such as GBK,GB2312 and GB18030

This snippet of Python 3 should convert your program correctly to work in Python 2.
def convertchar(char): #converts individual characters
if 32<=ord(char)<=126 or char=="\n": return char #if normal character, return it
h=hex(ord(char))[2:]
if ord(char)<256: #if unprintable ASCII
h=" "*(2-len(h))+h
return "\\x"+h
elif ord(char)<65536: #if short unicode
h=" "*(4-len(h))+h
return "\\u"+h
else: #if long unicode
h=" "*(8-len(h))+h
return "\\U"+h
def converttext(text): #converts a chunk of text
newtext=""
for char in text:
newtext+=convertchar(char)
return newtext
def convertfile(oldfilename,newfilename): #converts a file
oldfile=open(oldfilename,"r")
oldtext=oldfile.read()
oldfile.close()
newtext=converttext(oldtext)
newfile=open(newfilename,"w")
newfile.write(newtext)
newfile.close()
convertfile("FILE_TO_BE_CONVERTED","FILE_TO_STORE_OUTPUT")

First a simple remarl: as you are using byte strings in a Python2 script, the # -*- coding: utf-8 -*- has simply no effect. It only helps to convert the source byte string to an unicode string if you had written:
# -*- coding: utf-8 -*-
...
utxt = u'naïve' # source code is the bytestring `na\xc3\xafve'
# but utxt must become the unicode string u'na\xefve'
Simply it might be interpreted by clever editors to automatically use a utf8 charset.
Now for the actual question. Unfortunately, what you are asking for is not really trivial: idenfying in a source file what is in a comment and in a string simply requires a Python parser... And AFAIK, if you use the parser of ast modules you will lose your comments except for docstrings.
But in Python 2, non ASCII characters are only allowed in comments and litteral strings! So you can safely assume that if the source file is a correct Python 2 script containing no litteral unicode string(*), you can safely transform any non ascii character in its Python representation.
A possible Python function reading a raw source file from a file object and writing it after encoding in another file object could be:
def src_encode(infile, outfile):
while True:
c = infile.read(1)
if len(c) < 1: break # stop on end of file
if ord(c) > 127: # transform high characters
c = "\\x{:2x}".format(ord(c))
outfile.write(c)
An nice property is that it works whatever encoding you use, provided the source file is acceptable by a Python interpreter and does not contain high characters in unicode litterals(*), and the converted file will behave exactly the same as the original one...
(*) A problem will arise if you use unicode litterals in an encoding other that Latin1, because the above function will behave as if the file contained the declaration # -*- coding: Latin1 -*-: u'é' will be translated correctly as u'\xe9' if original encoding is latin1 but as u'\xc3\xc9' (not what is expected...) if original encoding is utf8, and I cannot imagine a way to process correctly both litteral byte strings and unicode byte strings without fully parsing the source file...

Python decoding issue with Chinese characters

I'm using Python 3.5, and I'm trying to take a block of byte text that may or may not contain special Chinese characters and output it to a file. It works for entries that do not contain Chinese characters, but breaks when they do. The Chinese characters are always a person's name, and are always in addition to the English spelling of their name. The text is JSON formatted and needs to be decoded before I can load it. The decoding seems to go fine and doesn't give me any errors. When I try and write the decoded text to a file it gives me the following error message:
UnicodeEncodeError: 'charmap' codec can't encode characters in position 14-18: character maps to undefined
Here is an example of the raw data that I get before I do anything to it:
b' "isBulkRecipient": "false",\r\n "name": "Name in, English \xef'
b'\xab\x62\xb6\xe2\x15\x8a\x8b\x8a\xee\xab\x89\xcf\xbc\x8a",\r\n
Here is the code that I am using:
recipientData = json.loads(recipientContent.decode('utf-8', 'ignore'))
recipientName = recipientData['signers'][0]['name']
pprint(recipientName)
with open('envelope recipient list.csv', 'a', newline='') as fp:
a = csv.writer(fp, delimiter=',')
csvData = [[recipientName]]
a.writerows(csvData)
The recipientContent is obtained from an API call. I do not need to have the Chinese characters in the output file. Any advice will be greatly appreciated!
Update:
I've been doing some manual workarounds for each entry that breaks, and came other entries that didn't contain Chinese special characters, but had them from other languages, and the broke the program as well. The special characters are only in the name field. So a name could be something like "Ałex" where it is a mixture of normal and special characters. Before i decode the string that contains this information i am able to print it out to the screen and it looks like this: b'name": "A\xc5ex",\r\n
But after i decode it into utf-8 it will give me an error if i try to output it. The error message is: UnicodeEncodeError: 'charmap' codec can't encode character 'u0142' in position 2- character maps to -undefined-
I looked up what \u0142 was and it is the ł special character.

The error you're getting is when you're writing to the file.
In Python 3.x, when you open() in text mode (the default) without specifying an encoding=, Python will use an encoding most suitable to your locale or language settings.
If you're on Windows, this will use the charmap codec to map to your language encoding.
Although you could just write bytes straight to a file, you're doing the right thing by decoding it first. As others have said, you should really decode using the encoding specified by the web server. You could also use Python Requests module, which does this for you. (You example doesn't decode as UTF-8, so I assume your example isn't correct)
To solve your immediate error, simply pass an encoding to open(), which supports the characters you have in your data. Unicode in UTF-8 encoding is the obvious choice. Therefore, you should change your code to read:
with open('envelope recipient list.csv', 'a', encoding='utf-8', newline='') as fp:

Warning: shotgun solution ahead
Assuming you just want to get rid of all foreign character in all your file ( that is they are not important for your future processing of all other fields), you can simply ignore all non ascii characters
recipientData = json.loads(recipientContent.decode('utf-8', 'ignore'))
by
recipientData = json.loads(recipientContent.decode('ascii', 'ignore'))
like this you remove all non ascii characters before future processing.
I called it shotgun solution because it might not work correctly under certain circumstances:
Obviously if non ascii characters are needed to keep for future use
If b'\' or b" characters appears for example from part of an utf-16 character.

Add this line to your code :
from __future__ import unicode_literals

How to read Chinese files?

I'm stuck with all this confusing encoding stuff. I have a file containing Chinese subs. I actually believe it is UTF-8 because using this in Notepad++ gives me a very good result. If I set gb2312 the Chinese part is still fine, but I will see some UTF8 code not being converted.
The goal is to loop through the text in the file and count how many times the different chars come up.
import os
import re
import io
character_dict = {}
for dirname, dirnames, filenames in os.walk('.'):
for filename in filenames:
if "srt" in filename:
import codecs
f = codecs.open(filename, 'r', 'gb2312', errors='ignore')
s = f.read()
# deleting {}
s = re.sub('{[^}]+}', '', s)
# deleting every line that does not start with a chinese char
s = re.sub(r'(?m)^[A-Z0-9a-z].*\n?', '', s)
# delete non chinese chars
s = re.sub(r'[\s\.A-Za-z0-9\?\!\\/\-\"\,\*]', '', s)
#print s
s = s.encode('gb2312')
print s
for c in s:
#print c
pass
This will actually give me the complete Chinese text. But when I print out the loop on the bottom I just get questionmarks instead of the single chars.
Also note I said it is UTF8, but I have to use gb2312 for encoding and as the setting in my gnome-terminal. If I set it to UTF8 in the code i just get trash no matter if I set my terminal to UTF8 or gb2312. So maybe this file is not UTF8 after all!?
In any case s contains the full Chinese text. Why can't I loop it?
Please help me to understand this. It is very confusing for me and the docs are getting me nowhere. And google just leads me to similar problems that somebody solves, but there is no explanation so far that helped me understand this.

gb2312 is a multi-byte encoding. If you iterate over a bytestring encoded with it, you will be iterating over the bytes, not over the characters you want to be counting (or printing). You probably want to do your iteration on the unicode string before encoding it. If necessary, you can encode the individual codepoints (characters) to their own bytestrings for output:
# don't do s = s.encode('gb2312')
for c in s: # iterate over the unicode codepoints
print c.encode('gb2312') # encode them individually for output, if necessary

You are printing individual bytes. GB2312 is a multi-byte encoding, and each codepoint uses 2 bytes. Printing those bytes individually won't produce valid output, no.
The solution is to not encode from Unicode to bytes when printing. Loop over the Unicode string instead:
# deleting {}
s = re.sub('{[^}]+}', '', s)
# deleting every line that does not start with a chinese char
s = re.sub(r'(?m)^[A-Z0-9a-z].*\n?', '', s)
# delete non chinese chars
s = re.sub(r'[\s\.A-Za-z0-9\?\!\\/\-\"\,\*]', '', s)
#print s
# No `s.encode()`!
for char in s:
print char
You could encode each char chararter individually:
for char in s:
print char
But if you have your console / IDE / terminal correctly configured you should be able to print directly without errors, especially since your print s.encode('gb2312)` produces correct output.
You also appear to be confusing UTF-8 (an encoding) with the Unicode standard. UTF-8 can be used to represent Unicode data in bytes. GB2312 is an encoding too, and can be used to represent a (subset of) Unicode text in bytes.
You may want to read up on Python and Unicode:
The Python Unicode HOWTO
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

Identify garbage unicode string using python

My script is reads data from csv file, the csv file can have multiple strings of English or non English words.
Some time the text file has garbage strings , i want to identify those string and skip those string and process others
doc = codecs.open(input_text_file, "rb",'utf_8_sig')
fob = csv.DictReader(doc)
for row, entry in enumerate(f):
if is_valid_unicode_str(row['Name']):
process_futher
def is_valid_unicode_str(value):
try:
function
return True
except UnicodeEncodeError:
return false
csv input:
"Name"
"袋è¢âdcx€¹Ã¤Â¸Å½Ã¦Å“‹å‹们çâ€ÂµÃ¥Â­Âå•â€"
"元大寶來證券"
"John Dove"
I want to defile function is_valid_unicode_str() which will identify the garbage string and process valid one only.
I tried to use decode is but it doesnt failed while decoding garbage strings
value.decode('utf8')
The expected output are string with Chinese and English string to be process
could you please guide me how can i implement function to filter valid Unicode files?.

(ftfy developer here)
I've figured out that the text is likely to be '袋袋与朋友们电子商'. I had to guess at the characters 友, 子, and 商, because some unprintable characters are characters missing in the string in your question. When guessing, I picked the most common character from the small number of possibilities. And I don't know where the "dcx" goes or why it's there.
Google Translate is not very helpful here but it seems to mean something about e-commerce.
So here's everything that happened to your text:
It was encoded as UTF-8 and decoded incorrectly as sloppy-windows-1252, twice
It had the letters "dcx" inserted into the middle of a UTF-8 sequence
Characters that don't exist in windows-1252 -- with byte values 81, 8d, 8f, 90, and 9d -- were removed
A non-breaking space (byte value a0) was removed from the end
If just the first problem had happened, ftfy.fix_text_encoding would be able to fix it. It's possible that the remaining problems just happened while you were trying to get the string onto Stack Overflow.
So here's my recommendation:
Find out who keeps decoding the data incorrectly as sloppy-windows-1252, and get them to decode it as UTF-8 instead.
If you end up with a string like this again, try ftfy.fix_text_encoding on it.

You have Mojibake strings; text encoded to one (correct) codec, then decoded as another.
In this case, your text was decoded with the Windows 1252 codepage; the U+20AC EURO SIGN in the text is typical of CP1252 Mojibakes. The original encoding could be one of the GB* family of Chinese encodings, or a multiple roundtrip UTF-8 - CP1252 Mojibake. Which one I cannot determine, I cannot read Chinese, nor do I have your full data; CP1252 Mojibakes include un-printable characters like 0x81 and 0x8D bytes that might have gotten lost when you posted your question here.
I'd install the ftfy project; it won't fix GB* encodings (I requested the project add support), but it includes a new codec called sloppy-windows-1252 that'll let you reverse an erroneous decode with that codec:
>>> import ftfy # registers extra codecs on import
>>> text = u'袋è¢âdcx€¹Ã¤Â¸Å½Ã¦Å“‹å‹们çâ€ÂµÃ¥Â­Âå•â€'
>>> print text.encode('sloppy-windows-1252').decode('gb2312', 'replace')
猫垄�姑�⑩dcx�盲赂沤忙��姑ヂ�姑ぢ宦�р�得ヂ�氓�⑩�
>>> print text.encode('sloppy-windows-1252').decode('gbk', 'replace')
猫垄鈥姑�⑩dcx�盲赂沤忙艙鈥姑ヂ鈥姑ぢ宦�р�得ヂ�氓鈥⑩�
>>> print text.encode('sloppy-windows-1252').decode('gb18030', 'replace')
猫垄鈥姑⑩dcx�盲赂沤忙艙鈥姑ヂ鈥姑ぢ宦р�得ヂ氓鈥⑩�
>>> print text.encode('sloppy-windows-1252').decode('utf8', 'ignore').encode('sloppy-windows-1252').decode('utf8', 'replace')
袋�dcx与朋�们���
The � U+FFFD REPLACEMENT CHARACTER shows the decoding wasn't entirely successful, but that could be due to the fact that your copied string here is missing anything not printable or using the 0x81 or 0x8D bytes.
You can try to fix your data this way; from the file data, try to decode to one of the GB* codecs after encoding to sloppy-windows-1252, or roundtrip from UTF-8 twice and see what fits best.
If that's not good enough (you cannot fix the data) you can use the ftfy.badness.sequence_weirdness() function to try and detect the issue:
>>> from ftfy.badness import sequence_weirdness
>>> sequence_weirdness(text)
9
>>> sequence_weirdness(u'元大寶來證券')
0
>>> sequence_weirdness(u'John Dove')
0
Mojibakes score high on the sequence weirdness scale. You'd could try and find an appropriate threshold for your data by which time you'd call the data most likely to be corrupted.
However, I think we can use a non-zero return value as a starting point for another test. English text should score 0 on that scale, and so should Chinese text. Chinese mixed with English can still score over 0, but you could not then encode that Chinese text to the CP-1252 codec while you can with the broken text:
from ftfy.badness import sequence_weirdness
def is_valid_unicode_str(text):
if not sequence_weirdness(text):
# nothing weird, should be okay
return True
try:
text.encode('sloppy-windows-1252')
except UnicodeEncodeError:
# Not CP-1252 encodable, probably fine
return True
else:
# Encodable as CP-1252, Mojibake alert level high
return False