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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.

How to use "with open as f" for all files within a directory [duplicate]

This question already has answers here:
Python, Unicode, and the Windows console
(15 answers)
Closed 5 years ago.
I am writing a Python (Python 3.3) program to send some data to a webpage using POST method. Mostly for debugging process I am getting the page result and displaying it on the screen using print() function.
The code is like this:
conn.request("POST", resource, params, headers)
response = conn.getresponse()
print(response.status, response.reason)
data = response.read()
print(data.decode('utf-8'));
the HTTPResponse .read() method returns a bytes element encoding the page (which is a well formated UTF-8 document) It seemed okay until I stopped using IDLE GUI for Windows and used the Windows console instead. The returned page has a U+2014 character (em-dash) which the print function translates well in the Windows GUI (I presume Code Page 1252) but does not in the Windows Console (Code Page 850). Given the strict default behavior I get the following error:
UnicodeEncodeError: 'charmap' codec can't encode character '\u2014' in position 10248: character maps to <undefined>
I could fix it using this quite ugly code:
print(data.decode('utf-8').encode('cp850','replace').decode('cp850'))
Now it replace the offending character "—" with a ?. Not the ideal case (a hyphen should be a better replacement) but good enough for my purpose.
There are several things I do not like from my solution.
The code is ugly with all that decoding, encoding, and decoding.
It solves the problem for just this case. If I port the program for a system using some other encoding (latin-1, cp437, back to cp1252, etc.) it should recognize the target encoding. It does not. (for instance, when using again the IDLE GUI, the emdash is also lost, which didn't happen before)
It would be nicer if the emdash translated to a hyphen instead of a interrogation bang.
The problem is not the emdash (I can think of several ways to solve that particularly problem) but I need to write robust code. I am feeding the page with data from a database and that data can come back. I can anticipate many other conflicting cases: an 'Á' U+00c1 (which is possible in my database) could translate into CP-850 (DOS/Windows Console encodign for Western European Languages) but not into CP-437 (encoding for US English, which is default in many Windows instalations).
So, the question:
Is there a nicer solution that makes my code agnostic from the output interface encoding?

I see three solutions to this:
Change the output encoding, so it will always output UTF-8. See e.g. Setting the correct encoding when piping stdout in Python, but I could not get these example to work.
Following example code makes the output aware of your target charset.
# -*- coding: utf-8 -*-
import sys
print sys.stdout.encoding
print u"Stöcker".encode(sys.stdout.encoding, errors='replace')
print u"Стоескер".encode(sys.stdout.encoding, errors='replace')
This example properly replaces any non-printable character in my name with a question mark.
If you create a custom print function, e.g. called myprint, using that mechanisms to encode output properly you can simply replace print with myprint whereever necessary without making the whole code look ugly.
Reset the output encoding globally at the begin of the software:
The page http://www.macfreek.nl/memory/Encoding_of_Python_stdout has a good summary what to do to change output encoding. Especially the section "StreamWriter Wrapper around Stdout" is interesting. Essentially it says to change the I/O encoding function like this:
In Python 2:
if sys.stdout.encoding != 'cp850':
sys.stdout = codecs.getwriter('cp850')(sys.stdout, 'strict')
if sys.stderr.encoding != 'cp850':
sys.stderr = codecs.getwriter('cp850')(sys.stderr, 'strict')
In Python 3:
if sys.stdout.encoding != 'cp850':
sys.stdout = codecs.getwriter('cp850')(sys.stdout.buffer, 'strict')
if sys.stderr.encoding != 'cp850':
sys.stderr = codecs.getwriter('cp850')(sys.stderr.buffer, 'strict')
If used in CGI outputting HTML you can replace 'strict' by 'xmlcharrefreplace' to get HTML encoded tags for non-printable characters.
Feel free to modify the approaches, setting different encodings, .... Note that it still wont work to output non-specified data. So any data, input, texts must be correctly convertable into unicode:
# -*- coding: utf-8 -*-
import sys
import codecs
sys.stdout = codecs.getwriter("iso-8859-1")(sys.stdout, 'xmlcharrefreplace')
print u"Stöcker" # works
print "Stöcker".decode("utf-8") # works
print "Stöcker" # fails

Based on Dirk Stöcker's answer, here's a neat wrapper function for Python 3's print function. Use it just like you would use print.
As an added bonus, compared to the other answers, this won't print your text as a bytearray ('b"content"'), but as normal strings ('content'), because of the last decode step.
def uprint(*objects, sep=' ', end='\n', file=sys.stdout):
enc = file.encoding
if enc == 'UTF-8':
print(*objects, sep=sep, end=end, file=file)
else:
f = lambda obj: str(obj).encode(enc, errors='backslashreplace').decode(enc)
print(*map(f, objects), sep=sep, end=end, file=file)
uprint('foo')
uprint(u'Antonín Dvořák')
uprint('foo', 'bar', u'Antonín Dvořák')

For debugging purposes, you could use print(repr(data)).
To display text, always print Unicode. Don't hardcode the character encoding of your environment such as Cp850 inside your script. To decode the HTTP response, see A good way to get the charset/encoding of an HTTP response in Python.
To print Unicode to Windows console, you could use win-unicode-console package.

I dug deeper into this and found the best solutions are here.
http://blog.notdot.net/2010/07/Getting-unicode-right-in-Python
In my case I solved "UnicodeEncodeError: 'charmap' codec can't encode character "
original code:
print("Process lines, file_name command_line %s\n"% command_line))
New code:
print("Process lines, file_name command_line %s\n"% command_line.encode('utf-8'))

If you are using Windows command line to print the data, you should use
chcp 65001
This worked for me!

If you use Python 3.6 (possibly 3.5 or later), it doesn't give that error to me anymore. I had a similar issue, because I was using v3.4, but it went away after I uninstalled and reinstalled.

Python 2 and 3 compatible way to print unicode that degrades gracefully [duplicate]

I'm trying to find a generic solution to print unicode strings from a python script.
The requirements are that it must run in both python 2.7 and 3.x, on any platform, and with any terminal settings and environment variables (e.g. LANG=C or LANG=en_US.UTF-8).
The python print function automatically tries to encode to the terminal encoding when printing, but if the terminal encoding is ascii it fails.
For example, the following works when the environment "LANG=enUS.UTF-8":
x = u'\xea'
print(x)
But it fails in python 2.7 when "LANG=C":
UnicodeEncodeError: 'ascii' codec can't encode character u'\xea' in position 0: ordinal not in range(128)
The following works regardless of the LANG setting, but would not properly show unicode characters if the terminal was using a different unicode encoding:
print(x.encode('utf-8'))
The desired behavior would be to always show unicode in the terminal if it is possible and show some encoding if the terminal does not support unicode. For example, the output would be UTF-8 encoded if the terminal only supported ascii. Basically, the goal is to do the same thing as the python print function when it works, but in the cases where the print function fails, use some default encoding.

You can handle the LANG=C case by telling sys.stdout to default to UTF-8 in cases when it would otherwise default to ASCII.
import sys, codecs
if sys.stdout.encoding is None or sys.stdout.encoding == 'ANSI_X3.4-1968':
utf8_writer = codecs.getwriter('UTF-8')
if sys.version_info.major < 3:
sys.stdout = utf8_writer(sys.stdout, errors='replace')
else:
sys.stdout = utf8_writer(sys.stdout.buffer, errors='replace')
print(u'\N{snowman}')
The above snippet fulfills your requirements: it works in Python 2.7 and 3.4, and it doesn't break when LANG is in a non-UTF-8 setting such as C.
It is not a new technique, but it's surprisingly hard to find in the documentation. As presented above, it actually respects non-UTF-8 settings such as ISO 8859-*. It only defaults to UTF-8 if Python would have bogusly defaulted to ASCII, breaking the application.

I don't think you should try and solve this at the Python level. Document your application requirements, log the locale of systems you run on so it can be included in bug reports and leave it at that.
If you do want to go this route, at least distinguish between terminals and pipes; you should never output data to a terminal that the terminal cannot explicitly handle; don't output UTF-8 for example, as the non-printable codepoints > U+007F could end up being interpreted as control codes when encoded.
For a pipe, output UTF-8 by default and make it configurable.
So you'd detect if a TTY is being used, then handle encoding based on that; for a terminal, set an error handler (pick one of replace or backslashreplace to provide replacement characters or escape sequences for whatever characters cannot be handled). For a pipe, use a configurable codec.
import codecs
import os
import sys
if os.isatty(sys.stdout.fileno()):
output_encoding = sys.stdout.encoding
errors = 'replace'
else:
output_encoding = 'utf-8' # allow override from settings
errors = None # perhaps parse from settings, not needed for UTF8
sys.stdout = codecs.getwriter(output_encoding)(sys.stdout, errors=errors)

You can encode the string yourself with the special parameter 'backslashreplace' so that unrepresentable characters are converted to escape sequences. In Python 2 you can print the result of encode directly, but in Python 3 you need to decode it back to Unicode first.
import sys
encoding = sys.stdout.encoding
print(s.encode(encoding, 'backslashreplace').decode(encoding))
If sys.stdout.encoding doesn't deliver the value that your terminal can handle, that's a separate problem that you must deal with.

You can handle the exception:
def always_print(s):
try:
print(s)
except UnicodeEncodeError:
print(s.encode('utf-8'))

'ascii' codec can't encode error when reading using Python to read JSON

Yet another person unable to find the correct magic incantation to get Python to print UTF-8 characters.
I have a JSON file. The JSON file contains string values. One of those string values contains the character "à". I have a Python program that reads in the JSON file and prints some of the strings in it. Sometimes when the program tries to print the string containing "à" I get the error
UnicodeEncodeError: 'ascii' codec can't encode character u'\xe0' in position 12: ordinal not in range(128)
This is hard to reproduce. Sometimes a slightly different program is able to print the string "à". A smaller JSON file containing only this string does not exhibit the problem. If I start sprinkling encode('utf-8') and decode('utf-8') around the code it changes what blows up in unpredictable ways. I haven't been able to create a minimal code fragment and input that exhibits this problem.
I load the JSON file like so.
with codecs.open(filename, 'r', 'utf-8') as f:
j = json.load(f)
I'll pull out the offending string like so.
s = j['key']
Later I do a print that has s as part of it and see the error.
I'm pretty sure the original file is in UTF-8 because in the interactive command line
codecs.open(filename, 'r', 'utf-8').read()
returns a string but
codecs.open(filename, 'r', 'ascii').read()
gives an error about the ascii codec not being able to decode such-and-such a byte. The file size in bytes is identical to the number of characters returned by wc -c, and I don't see anything else that looks like a non-ASCII character, so I suspect the problem lies entirely with this one high-ASCII "à".
I am not making any explicit calls to str() in my code.
I've been through the Python Unicode HOWTO multiple times. I understand that I'm supposed to "sandwich" unicode handling. I think I'm doing this, but obviously there's something I still misunderstand.
Mostly I'm confused because it seems like if I specify 'utf-8' in the codecs.open call, everything should be happening in UTF-8. I don't understand how the ASCII codec still sneaks in.
What am I doing wrong? How do I go about debugging this?
Edit: Used io module in place of codecs. Same result.
Edit: I don't have a minimal example, but at least I have a minimal repro scenario.
I am printing an object derived from the strings in the JSON that is causing the problem. So the following gives an error.
print(myobj)
(Note that I am using from __future__ import print_function though that does not appear to make a difference.)
Putting an encode('utf-8') on the end of my object's __str__ function return value does not fix the bug. However changing the print line to this does.
print("%s" % myobj)
This looks wrong to me. I'd expect these two print calls to be equivalent.
I can make this work by doing the sys.setdefaultencoding hack:
import sys
reload(sys)
sys.setdefaultencoding("UTF-8")
But this is apparently a bad idea that can make Python malfunction in other ways.
What is the correct way to do this? I tried
env PYTHONIOENCODING=UTF-8 ./myscript.py
but that didn't work. (Unsurprisingly, since the issue is the default encoding, not the io encoding.)

When you write directly to a file or redirect stdout to a file or pipe the default encoding is ASCII and you have to encode Unicode strings before writing them. With opened file handles you can set an encoding to have this happen automatically but with print you must use an encode() method.
print s.encode('utf-8')
It is recommended to use the newer io module in place of codecs because it has an improved implementation and is forward compatible with Py3.x open().

How to convert html entities into symbols?

I have made some adaptations to the script from this answer. and I am having problems with unicode. Some of the questions end up being written poorly.
Some answers and responses end up looking like:
Yeah.. I know.. I’m a simpleton.. So what’s a Singleton? (2)
How can I make the ’ to be translated to the right character?
Note: If that matters, I'm using python 2.6, on a French windows.
>>> sys.getdefaultencoding()
'ascii'
>>> sys.getfilesystemencoding()
'mbcs'
EDIT1: Based on Ryan Ginstrom's post, I have been able to correct a part of the output, but I am having problems with python's unicode.
In Idle / python shell:
Yeah.. I know.. I’m a simpleton.. So
what’s a Singleton?
In a text file, when redirecting stdout
Yeah.. I know.. I’m a simpleton.. So
what’s a Singleton?
How can I correct that ?
Edit2: I have tried Jarret Hardie's solution but it didn't do anything.
I am on windows, using python 2.6, so my site-packages folder is at:
C:\Python26\Lib\site-packages
There was no siteconfig.py file, so I created one, pasted the code provided by Jarret Hardie, started a python interpreter, but seems like it has not been loaded.
sys.getdefaultencoding()
'ascii'
I noticed there is a site.py file at :
C:\Python26\Lib\site.py
I tried changing the encoding in the function
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 !
to set the encoding to utf-8. It worked (after a restart of python of course).
>>> sys.getdefaultencoding()
'utf-8'
The sad thing is that it didn't correct the caracters in my program. :(

You should be able to convert HTMl/XML entities into Unicode characters. Check out this answer in SO:
Decoding HTML Entities With Python
Basically you want something like this:
from BeautifulSoup import BeautifulStoneSoup
soup = BeautifulStoneSoup(urllib2.urlopen(URL),
convertEntities=BeautifulStoneSoup.ALL_ENTITIES)

Does changing your default encoding in siteconfig.py work?
In your site-packages file (on my OS X system it's in /Library/Python/2.5/site-packages/) create a file called siteconfig.py. In this file put:
import sys
sys.setdefaultencoding('utf-8')
The setdefaultencoding method is removed from the sys module once siteconfig.py is processed, so you must put it in site-packages so that Python will read it when the interpreter starts up.