We Keep Coding

Encoding string in scrapy and dropping to JSON

I need need to scrape text data from sites using languages other than English (mostly Eastern European langs), using Scrapy. When Scrapy finishes, it needs to convert scraped data to JSON for further use.
The thing is, if I just scrape the text like this:
i['title'] = response.xpath('//home/title//text()').extract_first()
without encoding it, Scrapy throws something like this:
UnicodeEncodeError: 'charmap' codec can't encode character '\u0107' in position 103: character maps to <undefined>
On the other hand, if I do encode it, and try to process that with json.dumps(), I get a TypeError, since json can't serialize bytes. I've seen this explanation (How to encode bytes in JSON? json.dumps() throwing a TypeError), but its of little use, since I need to use utf-8 or utf-16, and not ascii.
Any idea how to solve this?

have you taken a look at the response headers? What encoding does it tell you? I can imagine that it tells you another encoding than it actually is.
Pythons decoding function has a parameter error ('strict', 'replace', 'ignore') which you can use to debug and find the problem'
Sorry this more a comment than an answer but i cant comment yet (too less rep)

'ascii' codec can't encode character u'\xe9'

I already tried all previous answers and solution.
I am trying to use this value, which gave me encoding related error.
ar = [u'http://dbpedia.org/resource/Anne_Hathaway', u'http://dbpedia.org/resource/Jodie_Bain', u'http://dbpedia.org/resource/Wendy_Divine', u'http://dbpedia.org/resource/Jos\xe9_El\xedas_Moreno', u'http://dbpedia.org/resource/Baaba_Maal']
So I tried,
d = [x.decode('utf-8') for x in ar]
which gives:
UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in position 31: ordinal not in range(128)
I tried out
d = [x.encode('utf-8') for x in ar]
which removes error but changes the original content
original value was u'http://dbpedia.org/resource/Jos\xe9_El\xedas_Moreno' which converted to 'http://dbpedia.org/resource/Jos\xc3\xa9_El\xc3\xadas_Moreno' while using encode
what is correct way to deal with this scenario?
Edit
Error comes when I feed these links in
req = urllib2.Request()

The second version of your string is the correct utf-8 representation of your original unicode string. If you want to have a meaningful comparison, you have to use the same representation for both the stored string and the user input string. The sane thing to do here is to always use Unicode string internally (in your code), and make sure both your user inputs and stored strings are correctly decoded to unicode from their respective encodings at your system's boundaries (storage subsystem and user inputs subsystem).
Also you seem to be a bit confused about unicode and encodings, so reading this and this might help.

Unicode strings in python are "raw" unicode, so make sure to .encode() and .decode() them as appropriate. Using utf8 encoding is considered a best practice among multiple dev groups all over the world.
To encode use the quote function from the urllib2 library:
from urllib2 import quote
escaped_string = quote(unicode_string.encode('utf-8'))
To decode, use unquote:
from urllib2 import unquote
src = "http://dbpedia.org/resource/Jos\xc3\xa9_El\xc3\xadas_Moreno"
unicode_string = unquote(src).decode('utf-8')
Also, if you're more interested in Unicode and UTF-8 work, check out Unicode HOWTO and

In your Unicode list, u'http://dbpedia.org/resource/Jos\xe9_El\xedas_Moreno' is an ASCII safe way to represent a Unicode string. When encoded in a form that supports the full Western European character set, such as UTF-8, it's: http://dbpedia.org/resource/José_Elías_Moreno
Your .encode("UTF-8") is correct and would have looked ok in a UTF-8 editor or browser. What you saw after the encode was an ASCII safe representation of UTF-8.
For example, your trouble chars were é and í.
é = 00E9 Unicode = C3A9 UTF-8
í = 00ED Unicode = C3AD UTF-8
In short, your .encode() method is correct and should be used for writing to files or to a browser.

python byte string encode and decode

I am trying to convert an incoming byte string that contains non-ascii characters into a valid utf-8 string such that I can dump is as json.
b = '\x80'
u8 = b.encode('utf-8')
j = json.dumps(u8)
I expected j to be '\xc2\x80' but instead I get:
UnicodeDecodeError: 'ascii' codec can't decode byte 0x80 in position 0: ordinal not in range(128)
In my situation, 'b' is coming from mysql via google protocol buffers and is filled out with some blob data.
Any ideas?
EDIT:
I have ethernet frames that are stored in a mysql table as a blob (please, everyone, stay on topic and keep from discussing why there are packets in a table). The table collation is utf-8 and the db layer (sqlalchemy, non-orm) is grabbing the data and creating structs (google protocol buffers) which store the blob as a python 'str'. In some cases I use the protocol buffers directly with out any issue. In other cases, I need to expose the same data via json. What I noticed is that when json.dumps() does its thing, '\x80' can be replaced with the invalid unicode char (\ufffd iirc)

You need to examine the documentation for the software API that you are using. BLOB is an acronym: BINARY Large Object.
If your data is in fact binary, the idea of decoding it to Unicode is of course a nonsense.
If it is in fact text, you need to know what encoding to use to decode it to Unicode.
Then you use json.dumps(a_Python_object) ... if you encode it to UTF-8 yourself, json will decode it back again:
>>> import json
>>> json.dumps(u"\u0100\u0404")
'"\\u0100\\u0404"'
>>> json.dumps(u"\u0100\u0404".encode('utf8'))
'"\\u0100\\u0404"'
>>>
UPDATE about latin1:
u'\x80' is a useless meaningless C1 control character -- the encoding is extremely unlikely to be Latin-1. Latin-1 is "a snare and a delusion" -- all 8-bit bytes are decoded to Unicode without raising an exception. Don't confuse "works" and "doesn't raise an exception".

Use b.decode('name of source encoding') to get a unicode version. This was surprising to me when I learned it. eg:
In [123]: 'foo'.decode('latin-1')
Out[123]: u'foo'

I think what you are trying to do is decode the string object of some encoding. Do you know what that encoding is? To get the unicode object.
unicode_b = b.decode('some_encoding')
and then re-encoding the unicode object using the utf_8 encoding back to a string object.
b = unicode_b.encode('utf_8')
Using the unicode object as a translator, without knowing what the original encoding of the string is I can't know for certain but there is the possibility that the conversion will not go as expected. The unicode object is not meant for converting strings of one encoding to another. I would work with the unicode object assuming you know what the encoding is, if you don't know what the encoding is then there really isn't a way to find out without trial and error, and then convert back to the encoded string when you want a string object back.

Python string encoding issue

I am using the Amazon MWS API to get the sales report for my store and then save that report in a table in the database. Unfortunately I am getting an encoding error when I try to encode the information as Unicode. After looking through the report (exactly as amazon sent it) I saw this string which is the location of the buyer:
'S�o Paulo'
so I tried to encode it like so:
encodeme = 'S�o Paulo'
encodeme.encode('utf-8)
but got the following error
UnicodeDecodeError: 'ascii' codec can't decode byte 0xef in position 1: ordinal not in range(128)
The whole reason why I am trying to encode it is because as soon as Django sees the � character it throws a warning and cuts off the string, meaning that the location is saved as S instead of
São Paulo
Any help is appreciated.

It looks like you are having some kind of encoding problem.
First, you should be very certain what encoding Amazon is using in the report body they send you. Is it UTF-8? Is it ISO 8859-1? Something else?
Unfortunately the Amazon MWS Reports API documentation, especially their API Reference, is not very forthcoming about what encoding they use. They only encoding I see them mention is UTF-8, so that should be your first guess. The GetReport API documentation (p.36-37) describes the response element Report as being type xs:string, but I don't see where they define that data type. Maybe they mean XML Schema's string datatype.
So, I suggest you save the byte sequence you are receiving as your report body from Amazon in a file, with zero transformations. Be aware that your code which calls AWS might be modifying the report body string inadvertently. Examine the non-ASCII bytes in that file with a binary editor. Is the "São" of "São" stored as S\xC3\xA3o, indicating UTF-8 encoding? Or is it stored as S\xE3o, indicating ISO 8859-1 encoding?
I'm guessing that you receive your report as a flat file. The Amazon AWS documentation says that you can request reports be delivered to you as XML. This would have the advantage of giving you a reply with an explicit encoding declaration.
Once you know the encoding of the report body, you now need to handle it properly. You imply that you are using the Django framework and Python language code to receive the report from Amazon AWS.
One thing to get very clear (as Skirmantas also explains):
Unicode strings hold characters. Byte strings hold bytes (octets).
Encoding converts a Unicode string into a byte string.
Decoding converts a byte string into a Unicode string.
The string you get from Amazon AWS is a byte string. You need to decode it to get a Unicode string. But your code fragment, encodeme = 'São Paulo', gives you a byte string. encodeme.encode('utf-8) performs an encode() on the byte string, which isn't what you want. (The missing closing quote on 'utf-8 doesn't help.)
Try this example code:
>>> reportbody = 'S\xc3\xa3o Paulo' # UTF-8 encoded byte string
>>> reportbody.decode('utf-8') # returns a Unicode string, u'...'
u'S\xe3o Paulo'
You might find some background reading helpful. I agree with Hoxieboy that you should take the time to read Python's Unicode HOWTO. Also check out the top answers to What do I need to know about Unicode?.

I think you have to decode it using a correct encoding rather than encode it to utf-8. Try
s = s.decode('utf-8')
However you need to know which encoding to use. Input can come in other encodings that utf-8.
The error which you received UnicodeDecodeError means that your object is not unicode, it is a bytestring. When you do bytestring.encode, the string firstly is decoded into unicode object with default encoding (ascii) and only then it is encoded with utf-8.
I'll try to explain the difference of unicode string and utf-8 bytestring in python.
unicode is a python's datatype which represents a unicode string. You use unicode for most of string operations in your program. Python probably uses utf-8 in its internals though it could also be utf-16 and this doesn't matter for you.
bytestring is a binary safe string. It can be of any encoding. When you receive data, for example you open a file, you get a bytestring and in most cases you will want to decode it to unicode. When you write to file you have to encode unicode objects into bytestrings. Sometimes decoding/encoding is done for you by a framework or library. Not always however framework can do this because not always framework can known which encoding to use.
utf-8 is an encoding which can correctly represent any unicode string as a bytestring. However you can't decode any kind of bytestring with utf-8 into unicode. You need to know what encoding is used in the bytestring to decode it.

Official Python unicode documentation
You might try that webpage if you haven't already and see if you can get the answer you're looking for ;)

Python: convert string from UTF-8 to Latin-1

I feel stacked here trying to change encodings with Python 2.5
I have XML response, which I encode to UTF-8: response.encode('utf-8'). That is fine, but the program which uses this info doesn't like this encoding and I have to convert it to other code page. Real example is that I use ghostscript python module to embed pdfmark data to a PDF file - end result is with wrong characters in Acrobat.
I've done numerous combinations with .encode() and .decode() between 'utf-8' and 'latin-1' and it drives me crazy as I can't output correct result.
If I output the string to a file with .encode('utf-8') and then convert this file from UTF-8 to CP1252 (aka latin-1) with i.e. iconv.exe and embed the data everything is fine.
Basically can someone help me convert i.e. character á which is UTF-8 encoded as hex: C3 A1 to latin-1 as hex: E1?

Instead of .encode('utf-8'), use .encode('latin-1').

data="UTF-8 data"
udata=data.decode("utf-8")
data=udata.encode("latin-1","ignore")
Should do it.

Can you provide more details about what you are trying to do? In general, if you have a unicode string, you can use encode to convert it into string with appropriate encoding. Eg:
>>> a = u"\u00E1"
>>> type(a)
<type 'unicode'>
>>> a.encode('utf-8')
'\xc3\xa1'
>>> a.encode('latin-1')
'\xe1'

If the previous answers do not solve your problem, check the source of the data that won't print/convert properly.
In my case, I was using json.load on data incorrectly read from file by not using the encoding="utf-8". Trying to de-/encode the resulting string to latin-1 just does not help...