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How to write strings in Unicode to a text file in Python? [duplicate]

I'm having some brain failure in understanding reading and writing text to a file (Python 2.4).
# The string, which has an a-acute in it.
ss = u'Capit\xe1n'
ss8 = ss.encode('utf8')
repr(ss), repr(ss8)
("u'Capit\xe1n'", "'Capit\xc3\xa1n'")
print ss, ss8
print >> open('f1','w'), ss8
>>> file('f1').read()
'Capit\xc3\xa1n\n'
So I type in Capit\xc3\xa1n into my favorite editor, in file f2.
Then:
>>> open('f1').read()
'Capit\xc3\xa1n\n'
>>> open('f2').read()
'Capit\\xc3\\xa1n\n'
>>> open('f1').read().decode('utf8')
u'Capit\xe1n\n'
>>> open('f2').read().decode('utf8')
u'Capit\\xc3\\xa1n\n'
What am I not understanding here? Clearly there is some vital bit of magic (or good sense) that I'm missing. What does one type into text files to get proper conversions?
What I'm truly failing to grok here, is what the point of the UTF-8 representation is, if you can't actually get Python to recognize it, when it comes from outside. Maybe I should just JSON dump the string, and use that instead, since that has an asciiable representation! More to the point, is there an ASCII representation of this Unicode object that Python will recognize and decode, when coming in from a file? If so, how do I get it?
>>> print simplejson.dumps(ss)
'"Capit\u00e1n"'
>>> print >> file('f3','w'), simplejson.dumps(ss)
>>> simplejson.load(open('f3'))
u'Capit\xe1n'

Rather than mess with .encode and .decode, specify the encoding when opening the file. The io module, added in Python 2.6, provides an io.open function, which allows specifying the file's encoding.
Supposing the file is encoded in UTF-8, we can use:
>>> import io
>>> f = io.open("test", mode="r", encoding="utf-8")
Then f.read returns a decoded Unicode object:
>>> f.read()
u'Capit\xe1l\n\n'
In 3.x, the io.open function is an alias for the built-in open function, which supports the encoding argument (it does not in 2.x).
We can also use open from the codecs standard library module:
>>> import codecs
>>> f = codecs.open("test", "r", "utf-8")
>>> f.read()
u'Capit\xe1l\n\n'
Note, however, that this can cause problems when mixing read() and readline().

In the notation u'Capit\xe1n\n' (should be just 'Capit\xe1n\n' in 3.x, and must be in 3.0 and 3.1), the \xe1 represents just one character. \x is an escape sequence, indicating that e1 is in hexadecimal.
Writing Capit\xc3\xa1n into the file in a text editor means that it actually contains \xc3\xa1. Those are 8 bytes and the code reads them all. We can see this by displaying the result:
# Python 3.x - reading the file as bytes rather than text,
# to ensure we see the raw data
>>> open('f2', 'rb').read()
b'Capit\\xc3\\xa1n\n'
# Python 2.x
>>> open('f2').read()
'Capit\\xc3\\xa1n\n'
Instead, just input characters like á in the editor, which should then handle the conversion to UTF-8 and save it.
In 2.x, a string that actually contains these backslash-escape sequences can be decoded using the string_escape codec:
# Python 2.x
>>> print 'Capit\\xc3\\xa1n\n'.decode('string_escape')
Capitán
The result is a str that is encoded in UTF-8 where the accented character is represented by the two bytes that were written \\xc3\\xa1 in the original string. To get a unicode result, decode again with UTF-8.
In 3.x, the string_escape codec is replaced with unicode_escape, and it is strictly enforced that we can only encode from a str to bytes, and decode from bytes to str. unicode_escape needs to start with a bytes in order to process the escape sequences (the other way around, it adds them); and then it will treat the resulting \xc3 and \xa1 as character escapes rather than byte escapes. As a result, we have to do a bit more work:
# Python 3.x
>>> 'Capit\\xc3\\xa1n\n'.encode('ascii').decode('unicode_escape').encode('latin-1').decode('utf-8')
'Capitán\n'

Now all you need in Python3 is open(Filename, 'r', encoding='utf-8')
[Edit on 2016-02-10 for requested clarification]
Python3 added the encoding parameter to its open function. The following information about the open function is gathered from here: https://docs.python.org/3/library/functions.html#open
open(file, mode='r', buffering=-1,
encoding=None, errors=None, newline=None,
closefd=True, opener=None)
Encoding is the name of the encoding used to decode or encode the
file. This should only be used in text mode. The default encoding is
platform dependent (whatever locale.getpreferredencoding()
returns), but any text encoding supported by Python can be used.
See the codecs module for the list of supported encodings.
So by adding encoding='utf-8' as a parameter to the open function, the file reading and writing is all done as utf8 (which is also now the default encoding of everything done in Python.)

So, I've found a solution for what I'm looking for, which is:
print open('f2').read().decode('string-escape').decode("utf-8")
There are some unusual codecs that are useful here. This particular reading allows one to take UTF-8 representations from within Python, copy them into an ASCII file, and have them be read in to Unicode. Under the "string-escape" decode, the slashes won't be doubled.
This allows for the sort of round trip that I was imagining.

This works for reading a file with UTF-8 encoding in Python 3.2:
import codecs
f = codecs.open('file_name.txt', 'r', 'UTF-8')
for line in f:
print(line)

# -*- encoding: utf-8 -*-
# converting a unknown formatting file in utf-8
import codecs
import commands
file_location = "jumper.sub"
file_encoding = commands.getoutput('file -b --mime-encoding %s' % file_location)
file_stream = codecs.open(file_location, 'r', file_encoding)
file_output = codecs.open(file_location+"b", 'w', 'utf-8')
for l in file_stream:
file_output.write(l)
file_stream.close()
file_output.close()

Aside from codecs.open(), io.open() can be used in both 2.x and 3.x to read and write text files. Example:
import io
text = u'á'
encoding = 'utf8'
with io.open('data.txt', 'w', encoding=encoding, newline='\n') as fout:
fout.write(text)
with io.open('data.txt', 'r', encoding=encoding, newline='\n') as fin:
text2 = fin.read()
assert text == text2

To read in an Unicode string and then send to HTML, I did this:
fileline.decode("utf-8").encode('ascii', 'xmlcharrefreplace')
Useful for python powered http servers.

Well, your favorite text editor does not realize that \xc3\xa1 are supposed to be character literals, but it interprets them as text. That's why you get the double backslashes in the last line -- it's now a real backslash + xc3, etc. in your file.
If you want to read and write encoded files in Python, best use the codecs module.
Pasting text between the terminal and applications is difficult, because you don't know which program will interpret your text using which encoding. You could try the following:
>>> s = file("f1").read()
>>> print unicode(s, "Latin-1")
Capitán
Then paste this string into your editor and make sure that it stores it using Latin-1. Under the assumption that the clipboard does not garble the string, the round trip should work.

You have stumbled over the general problem with encodings: How can I tell in which encoding a file is?
Answer: You can't unless the file format provides for this. XML, for example, begins with:
<?xml encoding="utf-8"?>
This header was carefully chosen so that it can be read no matter the encoding. In your case, there is no such hint, hence neither your editor nor Python has any idea what is going on. Therefore, you must use the codecs module and use codecs.open(path,mode,encoding) which provides the missing bit in Python.
As for your editor, you must check if it offers some way to set the encoding of a file.
The point of UTF-8 is to be able to encode 21-bit characters (Unicode) as an 8-bit data stream (because that's the only thing all computers in the world can handle). But since most OSs predate the Unicode era, they don't have suitable tools to attach the encoding information to files on the hard disk.
The next issue is the representation in Python. This is explained perfectly in the comment by heikogerlach. You must understand that your console can only display ASCII. In order to display Unicode or anything >= charcode 128, it must use some means of escaping. In your editor, you must not type the escaped display string but what the string means (in this case, you must enter the umlaut and save the file).
That said, you can use the Python function eval() to turn an escaped string into a string:
>>> x = eval("'Capit\\xc3\\xa1n\\n'")
>>> x
'Capit\xc3\xa1n\n'
>>> x[5]
'\xc3'
>>> len(x[5])
1
As you can see, the string "\xc3" has been turned into a single character. This is now an 8-bit string, UTF-8 encoded. To get Unicode:
>>> x.decode('utf-8')
u'Capit\xe1n\n'
Gregg Lind asked: I think there are some pieces missing here: the file f2 contains: hex:
0000000: 4361 7069 745c 7863 335c 7861 316e Capit\xc3\xa1n
codecs.open('f2','rb', 'utf-8'), for example, reads them all in a separate chars (expected) Is there any way to write to a file in ASCII that would work?
Answer: That depends on what you mean. ASCII can't represent characters > 127. So you need some way to say "the next few characters mean something special" which is what the sequence "\x" does. It says: The next two characters are the code of a single character. "\u" does the same using four characters to encode Unicode up to 0xFFFF (65535).
So you can't directly write Unicode to ASCII (because ASCII simply doesn't contain the same characters). You can write it as string escapes (as in f2); in this case, the file can be represented as ASCII. Or you can write it as UTF-8, in which case, you need an 8-bit safe stream.
Your solution using decode('string-escape') does work, but you must be aware how much memory you use: Three times the amount of using codecs.open().
Remember that a file is just a sequence of bytes with 8 bits. Neither the bits nor the bytes have a meaning. It's you who says "65 means 'A'". Since \xc3\xa1 should become "à" but the computer has no means to know, you must tell it by specifying the encoding which was used when writing the file.

The \x.. sequence is something that's specific to Python. It's not a universal byte escape sequence.
How you actually enter in UTF-8-encoded non-ASCII depends on your OS and/or your editor. Here's how you do it in Windows. For OS X to enter a with an acute accent you can just hit option + E, then A, and almost all text editors in OS X support UTF-8.

You can also improve the original open() function to work with Unicode files by replacing it in place, using the partial function. The beauty of this solution is you don't need to change any old code. It's transparent.
import codecs
import functools
open = functools.partial(codecs.open, encoding='utf-8')

I was trying to parse iCal using Python 2.7.9:
from icalendar import Calendar
But I was getting:
Traceback (most recent call last):
File "ical.py", line 92, in parse
print "{}".format(e[attr])
UnicodeEncodeError: 'ascii' codec can't encode character u'\xe1' in position 7: ordinal not in range(128)
and it was fixed with just:
print "{}".format(e[attr].encode("utf-8"))
(Now it can print liké á böss.)

I found the most simple approach by changing the default encoding of the whole script to be 'UTF-8':
import sys
reload(sys)
sys.setdefaultencoding('utf8')
any open, print or other statement will just use utf8.
Works at least for Python 2.7.9.
Thx goes to https://markhneedham.com/blog/2015/05/21/python-unicodeencodeerror-ascii-codec-cant-encode-character-uxfc-in-position-11-ordinal-not-in-range128/ (look at the end).

json.dump() uses ASCII codec encoding (instead of requested UTF-8) when redirecting stdout to a file

This tiny python program:
#!/usr/bin/env python
# -*- coding: utf8 -*-
import json
import sys
x = { "name":u"This doesn't work β" }
json.dump(x, sys.stdout, ensure_ascii=False, encoding="utf8")
print
Generates this output when run at a terminal:
$ ./tester.py
{"name": "This doesn't work β"}
Which is exactly as I would expect. However, if I redirect stdout to a file, it fails:
$ ./tester.py > output.json
Traceback (most recent call last):
File "./tester.py", line 9, in <module>
json.dump(x, sys.stdout, ensure_ascii=False, encoding="utf8")
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/__init__.py", line 190, in dump
fp.write(chunk)
UnicodeEncodeError: 'ascii' codec can't encode character u'\u03b2' in position 19: ordinal not in range(128)
However, a direct print (without json.dump) can can be redirect to file:
print u"This does work β".encode('utf-8')
It's as if the json package ignores the encoding option if stdout is not a terminal.
How can I get the json package to do what I want?

JSON is a text serialization format (that incidentally has a recommended binary encoding), not a binary serialization format. The json module itself only cares about encoding to the extent that it would like to know what Python 2's terrible str type is supposed to represent (is it ASCII bytes? UTF-8 bytes? latin-1 bytes?).
Since Python 2 text handling is, as stated, terrible, the json module is happy to return either str (when ensure_ascii is true, or the stars align in other cases and it's convinced you've told it str is compatible with your expected encoding, and none of the inputs are actually unicode) or unicode (when ensure_ascii is false, most of the time).
Like the rest of Python 2, sys.stdout is a bit wishy-washy. Even if it is set to an encoding='ascii' by your locale settings, it ignores it when you write a str to it (sys.stdout.write('\xe9') should fail, but instead, it treats the str as pre-encoded raw binary data and doesn't bother to verify it matches the expected encoding. But when unicode comes in, it doesn't have that option; unicode is text (not UTF-8 text, not ASCII text, etc.), from the ideal text world of unicorns and rainbows, and that world isn't expressed in tawdry bytes.
So sys.stdout must encode the result, and it does so with the locale determined encoding (sys.stdout.encoding will tell you what it is). When that's ASCII, and it receives something that can't encode to ASCII, it explodes (as it should).
The point is, the json module is always returning text (either unicode, or str that it's convinced is effectively text in the wishy-washy Python 2 world), and sometimes you get lucky and that text happens to be in a format that bypasses checks in sys.stdout.
But you shouldn't be relying on that. If your output must be in a specific encoding, use that encoding. The simplest way to do this (simplest in the sense that it pushes most work to the interpreter to do for you) is to not use sys.stdout (explicitly, or implicitly via print) and write your data to files you open with io.open (a backport of Python 3's open, that properly handles encodings), explicitly specifying encoding='utf-8'. If you must use sys.stdout, and you insist on ignoring the locale encoding, you can rewrap it, e.g.:
with io.open(sys.stdout.fileno(), encoding='utf-8', closefd=False) as encodedout:
json.dump(x, encodedout, ensure_ascii=False, encoding="utf-8")
which temporarily wraps the stdout file descriptor in a modern file-like object (using closefd to avoid closing the underlying descriptor when it's closed).
TL;DR: Switch to Python 3. Python 2 is awful when it comes to non-ASCII text, and its modules are often even worse (json should absolutely be returning a consistent type, or at least just one type for each setting of ensure_ascii, not dynamically selecting based on the inputs and encoding; it's not even the worst either, the csv module is absolutely awful). Also, it's reached end-of-life, and will not be patched for anything from here on out, so continuing to use it leaves you vulnerable to any security problems found between the beginning of this year and the end of time. Among other things, Python 3 uses str exclusively for text (which has the full Unicode support of Py2's unicode type) and modern Python 3 (3.7+) will coerce ASCII locales to UTF-8 (because basically all systems can actually handle the latter), which should fix all your problems. Non-ASCII text will behave the same as ASCII text, and weirdo locales like yours that insist they're ASCII (and therefore won't handle non-ASCII output) will be "fixed" to work as you desire, without manually encoding and decoding, rewrapping file handles, etc.

Consolidating all the comments and answers into one final answer:
Note: this answer is for Python 2.7. Python 3 is likely to be different.
The json spec says that json files are utf-8 encoded. However, the Python json package does not like to take chances and so writes straight ascii and escapes unicode characters in the output.
You can set the ensure_ascii flag to False, in which case the json package will generate unicode output instead of str. In that case, encoding the unicode output is your problem.
There is no way to make the json package generate utf-8 or any other encoding on output. It's either ascii or unicode; take your pick.
The encoding argument was a red herring. That option tells the json package how the input strings are encoded.
Here's what finally worked for me:
ofile = codecs.getwriter('utf-8')(sys.stdout)
json.dump(x, ofile, ensure_ascii=False)
tl;dr: the real mystery was why didn't it barf when just letting stdout go to the terminal. It turned out that stdout.write() was detecting when output was to a terminal and encoding per the $LANG environment variable. When output goes to a file, the unicode is encoded to ascii, and an error results when a non-encodable character is encountered.

There is an environment variable Python uses that can override encoding to the terminal or for redirection, so this should work without wrapping stdout inside the script.
$ export PYTHONIOENCODING=utf8
$ ./tester.py > output.json

Getting decoding error from server database [duplicate]

as3:~/ngokevin-site# nano content/blog/20140114_test-chinese.mkd
as3:~/ngokevin-site# wok
Traceback (most recent call last):
File "/usr/local/bin/wok", line 4, in
Engine()
File "/usr/local/lib/python2.7/site-packages/wok/engine.py", line 104, in init
self.load_pages()
File "/usr/local/lib/python2.7/site-packages/wok/engine.py", line 238, in load_pages
p = Page.from_file(os.path.join(root, f), self.options, self, renderer)
File "/usr/local/lib/python2.7/site-packages/wok/page.py", line 111, in from_file
page.meta['content'] = page.renderer.render(page.original)
File "/usr/local/lib/python2.7/site-packages/wok/renderers.py", line 46, in render
return markdown(plain, Markdown.plugins)
File "/usr/local/lib/python2.7/site-packages/markdown/init.py", line 419, in markdown
return md.convert(text)
File "/usr/local/lib/python2.7/site-packages/markdown/init.py", line 281, in convert
source = unicode(source)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe8 in position 1: ordinal not in range(128). -- Note: Markdown only accepts unicode input!
How to fix it?
In some other python-based static blog apps, Chinese post can be published successfully.
Such as this app: http://github.com/vrypan/bucket3. In my site http://bc3.brite.biz/, Chinese post can be published successfully.

tl;dr / quick fix
Don't decode/encode willy nilly
Don't assume your strings are UTF-8 encoded
Try to convert strings to Unicode strings as soon as possible in your code
Fix your locale: How to solve UnicodeDecodeError in Python 3.6?
Don't be tempted to use quick reload hacks
Unicode Zen in Python 2.x - The Long Version
Without seeing the source it's difficult to know the root cause, so I'll have to speak generally.
UnicodeDecodeError: 'ascii' codec can't decode byte generally happens when you try to convert a Python 2.x str that contains non-ASCII to a Unicode string without specifying the encoding of the original string.
In brief, Unicode strings are an entirely separate type of Python string that does not contain any encoding. They only hold Unicode point codes and therefore can hold any Unicode point from across the entire spectrum. Strings contain encoded text, beit UTF-8, UTF-16, ISO-8895-1, GBK, Big5 etc. Strings are decoded to Unicode and Unicodes are encoded to strings. Files and text data are always transferred in encoded strings.
The Markdown module authors probably use unicode() (where the exception is thrown) as a quality gate to the rest of the code - it will convert ASCII or re-wrap existing Unicodes strings to a new Unicode string. The Markdown authors can't know the encoding of the incoming string so will rely on you to decode strings to Unicode strings before passing to Markdown.
Unicode strings can be declared in your code using the u prefix to strings. E.g.
>>> my_u = u'my ünicôdé strįng'
>>> type(my_u)
<type 'unicode'>
Unicode strings may also come from file, databases and network modules. When this happens, you don't need to worry about the encoding.
Gotchas
Conversion from str to Unicode can happen even when you don't explicitly call unicode().
The following scenarios cause UnicodeDecodeError exceptions:
# Explicit conversion without encoding
unicode('€')
# New style format string into Unicode string
# Python will try to convert value string to Unicode first
u"The currency is: {}".format('€')
# Old style format string into Unicode string
# Python will try to convert value string to Unicode first
u'The currency is: %s' % '€'
# Append string to Unicode
# Python will try to convert string to Unicode first
u'The currency is: ' + '€'
Examples
In the following diagram, you can see how the word café has been encoded in either "UTF-8" or "Cp1252" encoding depending on the terminal type. In both examples, caf is just regular ascii. In UTF-8, é is encoded using two bytes. In "Cp1252", é is 0xE9 (which is also happens to be the Unicode point value (it's no coincidence)). The correct decode() is invoked and conversion to a Python Unicode is successfull:
In this diagram, decode() is called with ascii (which is the same as calling unicode() without an encoding given). As ASCII can't contain bytes greater than 0x7F, this will throw a UnicodeDecodeError exception:
The Unicode Sandwich
It's good practice to form a Unicode sandwich in your code, where you decode all incoming data to Unicode strings, work with Unicodes, then encode to strs on the way out. This saves you from worrying about the encoding of strings in the middle of your code.
Input / Decode
Source code
If you need to bake non-ASCII into your source code, just create Unicode strings by prefixing the string with a u. E.g.
u'Zürich'
To allow Python to decode your source code, you will need to add an encoding header to match the actual encoding of your file. For example, if your file was encoded as 'UTF-8', you would use:
# encoding: utf-8
This is only necessary when you have non-ASCII in your source code.
Files
Usually non-ASCII data is received from a file. The io module provides a TextWrapper that decodes your file on the fly, using a given encoding. You must use the correct encoding for the file - it can't be easily guessed. For example, for a UTF-8 file:
import io
with io.open("my_utf8_file.txt", "r", encoding="utf-8") as my_file:
my_unicode_string = my_file.read()
my_unicode_string would then be suitable for passing to Markdown. If a UnicodeDecodeError from the read() line, then you've probably used the wrong encoding value.
CSV Files
The Python 2.7 CSV module does not support non-ASCII characters 😩. Help is at hand, however, with https://pypi.python.org/pypi/backports.csv.
Use it like above but pass the opened file to it:
from backports import csv
import io
with io.open("my_utf8_file.txt", "r", encoding="utf-8") as my_file:
for row in csv.reader(my_file):
yield row
Databases
Most Python database drivers can return data in Unicode, but usually require a little configuration. Always use Unicode strings for SQL queries.
MySQL
In the connection string add:
charset='utf8',
use_unicode=True
E.g.
>>> db = MySQLdb.connect(host="localhost", user='root', passwd='passwd', db='sandbox', use_unicode=True, charset="utf8")
PostgreSQL
Add:
psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
psycopg2.extensions.register_type(psycopg2.extensions.UNICODEARRAY)
HTTP
Web pages can be encoded in just about any encoding. The Content-type header should contain a charset field to hint at the encoding. The content can then be decoded manually against this value. Alternatively, Python-Requests returns Unicodes in response.text.
Manually
If you must decode strings manually, you can simply do my_string.decode(encoding), where encoding is the appropriate encoding. Python 2.x supported codecs are given here: Standard Encodings. Again, if you get UnicodeDecodeError then you've probably got the wrong encoding.
The meat of the sandwich
Work with Unicodes as you would normal strs.
Output
stdout / printing
print writes through the stdout stream. Python tries to configure an encoder on stdout so that Unicodes are encoded to the console's encoding. For example, if a Linux shell's locale is en_GB.UTF-8, the output will be encoded to UTF-8. On Windows, you will be limited to an 8bit code page.
An incorrectly configured console, such as corrupt locale, can lead to unexpected print errors. PYTHONIOENCODING environment variable can force the encoding for stdout.
Files
Just like input, io.open can be used to transparently convert Unicodes to encoded byte strings.
Database
The same configuration for reading will allow Unicodes to be written directly.
Python 3
Python 3 is no more Unicode capable than Python 2.x is, however it is slightly less confused on the topic. E.g the regular str is now a Unicode string and the old str is now bytes.
The default encoding is UTF-8, so if you .decode() a byte string without giving an encoding, Python 3 uses UTF-8 encoding. This probably fixes 50% of people's Unicode problems.
Further, open() operates in text mode by default, so returns decoded str (Unicode ones). The encoding is derived from your locale, which tends to be UTF-8 on Un*x systems or an 8-bit code page, such as windows-1251, on Windows boxes.
Why you shouldn't use sys.setdefaultencoding('utf8')
It's a nasty hack (there's a reason you have to use reload) that will only mask problems and hinder your migration to Python 3.x. Understand the problem, fix the root cause and enjoy Unicode zen.
See Why should we NOT use sys.setdefaultencoding("utf-8") in a py script? for further details

Finally I got it:
as3:/usr/local/lib/python2.7/site-packages# cat sitecustomize.py
# encoding=utf8
import sys
reload(sys)
sys.setdefaultencoding('utf8')
Let me check:
as3:~/ngokevin-site# python
Python 2.7.6 (default, Dec 6 2013, 14:49:02)
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> reload(sys)
<module 'sys' (built-in)>
>>> sys.getdefaultencoding()
'utf8'
>>>
The above shows the default encoding of python is utf8. Then the error is no more.

This is the classic "unicode issue". I believe that explaining this is beyond the scope of a StackOverflow answer to completely explain what is happening.
It is well explained here.
In very brief summary, you have passed something that is being interpreted as a string of bytes to something that needs to decode it into Unicode characters, but the default codec (ascii) is failing.
The presentation I pointed you to provides advice for avoiding this. Make your code a "unicode sandwich". In Python 2, the use of from __future__ import unicode_literals helps.
Update: how can the code be fixed:
OK - in your variable "source" you have some bytes. It is not clear from your question how they got in there - maybe you read them from a web form? In any case, they are not encoded with ascii, but python is trying to convert them to unicode assuming that they are. You need to explicitly tell it what the encoding is. This means that you need to know what the encoding is! That is not always easy, and it depends entirely on where this string came from. You could experiment with some common encodings - for example UTF-8. You tell unicode() the encoding as a second parameter:
source = unicode(source, 'utf-8')

In some cases, when you check your default encoding (print sys.getdefaultencoding()), it returns that you are using ASCII. If you change to UTF-8, it doesn't work, depending on the content of your variable.
I found another way:
import sys
reload(sys)
sys.setdefaultencoding('Cp1252')

I was searching to solve the following error message:
unicodedecodeerror: 'ascii' codec can't decode byte 0xe2 in position 5454: ordinal not in range(128)
I finally got it fixed by specifying 'encoding':
f = open('../glove/glove.6B.100d.txt', encoding="utf-8")
Wish it could help you too.

"UnicodeDecodeError: 'ascii' codec can't decode byte"
Cause of this error: input_string must be unicode but str was given
"TypeError: Decoding Unicode is not supported"
Cause of this error: trying to convert unicode input_string into unicode
So first check that your input_string is str and convert to unicode if necessary:
if isinstance(input_string, str):
input_string = unicode(input_string, 'utf-8')
Secondly, the above just changes the type but does not remove non ascii characters. If you want to remove non-ascii characters:
if isinstance(input_string, str):
input_string = input_string.decode('ascii', 'ignore').encode('ascii') #note: this removes the character and encodes back to string.
elif isinstance(input_string, unicode):
input_string = input_string.encode('ascii', 'ignore')

In order to resolve this on an operating system level in an Ubuntu installation check the following:
$ locale charmap
If you get
locale: Cannot set LC_CTYPE to default locale: No such file or directory
instead of
UTF-8
then set LC_CTYPE and LC_ALL like this:
$ export LC_ALL="en_US.UTF-8"
$ export LC_CTYPE="en_US.UTF-8"

I find the best is to always convert to unicode - but this is difficult to achieve because in practice you'd have to check and convert every argument to every function and method you ever write that includes some form of string processing.
So I came up with the following approach to either guarantee unicodes or byte strings, from either input. In short, include and use the following lambdas:
# guarantee unicode string
_u = lambda t: t.decode('UTF-8', 'replace') if isinstance(t, str) else t
_uu = lambda *tt: tuple(_u(t) for t in tt)
# guarantee byte string in UTF8 encoding
_u8 = lambda t: t.encode('UTF-8', 'replace') if isinstance(t, unicode) else t
_uu8 = lambda *tt: tuple(_u8(t) for t in tt)
Examples:
text='Some string with codes > 127, like Zürich'
utext=u'Some string with codes > 127, like Zürich'
print "==> with _u, _uu"
print _u(text), type(_u(text))
print _u(utext), type(_u(utext))
print _uu(text, utext), type(_uu(text, utext))
print "==> with u8, uu8"
print _u8(text), type(_u8(text))
print _u8(utext), type(_u8(utext))
print _uu8(text, utext), type(_uu8(text, utext))
# with % formatting, always use _u() and _uu()
print "Some unknown input %s" % _u(text)
print "Multiple inputs %s, %s" % _uu(text, text)
# but with string.format be sure to always work with unicode strings
print u"Also works with formats: {}".format(_u(text))
print u"Also works with formats: {},{}".format(*_uu(text, text))
# ... or use _u8 and _uu8, because string.format expects byte strings
print "Also works with formats: {}".format(_u8(text))
print "Also works with formats: {},{}".format(*_uu8(text, text))
Here's some more reasoning about this.

Got a same error and this solved my error. Thanks!
python 2 and python 3 differing in unicode handling is making pickled files quite incompatible to load. So Use python pickle's encoding argument. Link below helped me solve the similar problem when I was trying to open pickled data from my python 3.7, while my file was saved originally in python 2.x version.
https://blog.modest-destiny.com/posts/python-2-and-3-compatible-pickle-save-and-load/
I copy the load_pickle function in my script and called the load_pickle(pickle_file) while loading my input_data like this:
input_data = load_pickle("my_dataset.pkl")
The load_pickle function is here:
def load_pickle(pickle_file):
try:
with open(pickle_file, 'rb') as f:
pickle_data = pickle.load(f)
except UnicodeDecodeError as e:
with open(pickle_file, 'rb') as f:
pickle_data = pickle.load(f, encoding='latin1')
except Exception as e:
print('Unable to load data ', pickle_file, ':', e)
raise
return pickle_data

Encode converts a unicode object in to a string object. I think you are trying to encode a string object. first convert your result into unicode object and then encode that unicode object into 'utf-8'.
for example
result = yourFunction()
result.decode().encode('utf-8')

This worked for me:
file = open('docs/my_messy_doc.pdf', 'rb')

I had the same error, with URLs containing non-ascii chars (bytes with values > 128), my solution:
url = url.decode('utf8').encode('utf-8')
Note: utf-8, utf8 are simply aliases . Using only 'utf8' or 'utf-8' should work in the same way
In my case, worked for me, in Python 2.7, I suppose this assignment changed 'something' in the str internal representation--i.e., it forces the right decoding of the backed byte sequence in url and finally puts the string into a utf-8 str with all the magic in the right place.
Unicode in Python is black magic for me.
Hope useful

I had the same problem but it didn't work for Python 3. I followed this and it solved my problem:
enc = sys.getdefaultencoding()
file = open(menu, "r", encoding = enc)
You have to set the encoding when you are reading/writing the file.

I got the same problem with the string "Pastelería Mallorca" and I solved with:
unicode("Pastelería Mallorca", 'latin-1')

In short, to ensure proper unicode handling in Python 2:
use io.open for reading/writing files
use from __future__ import unicode_literals
configure other data inputs/outputs (e.g., databases, network) to use unicode
if you cannot configure outputs to utf-8, convert your output for them print(text.encode('ascii', 'replace').decode())
For explanations, see #Alastair McCormack's detailed answer.

In a Django (1.9.10)/Python 2.7.5 project I have frequent UnicodeDecodeError exceptions; mainly when I try to feed unicode strings to logging. I made a helper function for arbitrary objects to basically format to 8-bit ascii strings and replacing any characters not in the table to '?'. I think it's not the best solution but since the default encoding is ascii (and i don't want to change it) it will do:
def encode_for_logging(c, encoding='ascii'):
if isinstance(c, basestring):
return c.encode(encoding, 'replace')
elif isinstance(c, Iterable):
c_ = []
for v in c:
c_.append(encode_for_logging(v, encoding))
return c_
else:
return encode_for_logging(unicode(c))
`

This error occurs when there are some non ASCII characters in our string and we are performing any operations on that string without proper decoding.
This helped me solve my problem.
I am reading a CSV file with columns ID,Text and decoding characters in it as below:
train_df = pd.read_csv("Example.csv")
train_data = train_df.values
for i in train_data:
print("ID :" + i[0])
text = i[1].decode("utf-8",errors="ignore").strip().lower()
print("Text: " + text)

Here is my solution, just add the encoding.
with open(file, encoding='utf8') as f
And because reading glove file will take a long time, I recommend to the glove file to a numpy file. When netx time you read the embedding weights, it will save your time.
import numpy as np
from tqdm import tqdm
def load_glove(file):
"""Loads GloVe vectors in numpy array.
Args:
file (str): a path to a glove file.
Return:
dict: a dict of numpy arrays.
"""
embeddings_index = {}
with open(file, encoding='utf8') as f:
for i, line in tqdm(enumerate(f)):
values = line.split()
word = ''.join(values[:-300])
coefs = np.asarray(values[-300:], dtype='float32')
embeddings_index[word] = coefs
return embeddings_index
# EMBEDDING_PATH = '../embedding_weights/glove.840B.300d.txt'
EMBEDDING_PATH = 'glove.840B.300d.txt'
embeddings = load_glove(EMBEDDING_PATH)
np.save('glove_embeddings.npy', embeddings)
Gist link: https://gist.github.com/BrambleXu/634a844cdd3cd04bb2e3ba3c83aef227

Specify: # encoding= utf-8 at the top of your Python File, It should fix the issue

I experienced this error with Python2.7. It happened to me while trying to run many python programs, but I managed to reproduce it with this simple script:
#!/usr/bin/env python
import subprocess
import sys
result = subprocess.Popen([u'svn', u'info'])
if not callable(getattr(result, "__enter__", None)) and not callable(getattr(result, "__exit__", None)):
print("foo")
print("bar")
On success, it should print out 'foo' and 'bar', and probably an error message if you're not in a svn folder.
On failure, it should print 'UnicodeDecodeError: 'ascii' codec can't decode byte 0xc4 in position 39: ordinal not in range(128)'.
After trying to regenerate my locales and many other solutions posted in this question, I learned the error was happening because I had a special character (ĺ) encoded in my PATH environment variable. After fixing the PATH in '~/.bashrc', and exiting my session and entering again, (apparently sourcing '~/.bashrc' didn't work), the issue was gone.

Writing UTF-8 friendly parsers in python

I wrote a simple file parser and writer, but then I came across an article talking about the importance of unicode and then it occurred to me that I'm assuming the input file is ascii encoded, which may not be the case all the time, though it would be rare in my situation.
In those rare cases, I would expect UTF-8 encoded files.
Is there a way to work with UTF-8 files by simply changing how I read and write? All I do with the strings is store them and then write them out, so I just need to make sure I can read them, store them, and write them properly.
Furthermore, would I have to treat ascii and UTF-8 files separately and write different functions for each? I have not worked with anything other than ascii files yet and only read about handling unicode.

Python natively supports Unicode. If you directly read and write from the first file to the second, then no data is lost as it copies the bytes verbatim. However, if you decode the string and then re-encode it, you'll need to make sure you use the right encoding.

If you are using Python 2, you can simply change all your str objects to unicode objects. Unicode objects have all the same methods as strings but are encoded in a unicode format instead of ASCII. See http://docs.python.org/library/functions.html#unicode .
If you are using Python 3, strings are encoded in UTF-8 by default.

If you are using Python 2.6 or later, you can use the io library and its io.open method to open the files you want. It has an encoding argument which should be set to 'utf-8' in your case. When you read or write the returned file objects, string are automatically en-/decoded.
Anyway, you don't need to do something special for ASCII, because UTF-8 is a superset of ASCII.

So long as you are only reading and writing to files and not expecting any other type of encoded input, then you should not have to do anything special.
% cat /tmp/u
π is 3.14.
% file /tmp/u
/tmp/u: UTF-8 Unicode text
% cat f.py
f = open('/tmp/u', 'r')
d = f.read()
print d.split()
f.close()
% python f.py
['\xcf\x80', 'is', '3.14.']
This changes when you declare or accept standard input using UTF-8.
% cat g.py
s = 'π is 3.14.'
print s.split()
% python g.py
File "g.py", line 1
SyntaxError: Non-ASCII character '\xcf' in file g.py on line 1, but no encoding declared; see http://www.python.org/peps/pep-0263.html for details
To handle this properly, declare the encoding for the Python program at the beginning per PEP 263 (referenced by the SyntaxError exception above).
% cat h.py
# -*- coding: utf-8 -*-
s = 'π is 3.14.'
print s.split()
% python h.py
['\xcf\x80', 'is', '3.14.']

python noob question about codecs and utf-8

Using python to pick it some pieces so definitely a noob ? here but didn't seeing a satisfactory answer.
I have a json utf-8 file with some pieces that have grave's, accute's etc.... I'm using codecs and have (for example):
str=codecs.open('../../publish_scripts/locations.json', 'r','utf-8')
locations=json.load(str)
for location in locations:
print location['name']
For print'ing, does anything special need to be done? It's giving me the following
ascii' codec can't encode character u'\xe9' in position 5
It looks like the correct utf-8 value for e-accute. I suspect I'm doing something wrong with print'ing. Would the iteration cause it to lose it's utf-8'ness?
PHP and Ruby versions handle the utf-8 piece fine; is there some looseness in those languages that python won't do?
thx

codec.open() will decode the contents of the file using the codec you supplied (utf-8). You then have a python unicode object (which behaves similarly to a string object).
Printing a unicode object will cause an implict (behind-the-scenes) encode using the default codec, which is usually ascii. If ascii cannot encode all of the characters present it will fail.
To print it, you should first encode it, thus:
for location in locations:
print location['name'].encode('utf8')
EDIT:
For your info, json.load() actually takes a file-like object (which is what codecs.open() returns). What you have at that point is neither a string nor a unicode object, but an iterable wrapper around the file.
By default json.load() expects the file to be utf8 encoded so your code snippet can be simplified:
locations = json.load(open('../../publish_scripts/locations.json'))
for location in locations:
print location['name'].encode('utf8')

You're probably reading the file correctly. The error occurs when you're printing. Python tries to convert the unicode string to ascii, and fails on the character in position 5.
Try this instead:
print location['name'].encode('utf-8')
If your terminal is set to expect output in utf-8 format, this will print correctly.

It's the same as in PHP. UTF8 strings are good to print.

The standard io streams are broken for non-ascii, character io in python2 and some site.py setups. Basically, you need to sys.setdefaultencoding('utf8') (or whatever the system locale's encoding is) very early in your script. With the site.py shipped in ubuntu, you need to imp.reload(sys) to make sys.setdefaultencoding available. Alternatively, you can wrap sys.stdout (and stdin and stderr) to be unicode-aware readers/writers, which you can get from codecs.getreader / getwriter.