How do I define strings read from a file as Unicode? [duplicate] - python

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Character reading from file in Python
I want to strip a input string from a file from all special characters, except for actual letters (even Cyrillic letters shouldn't be stripped). The solution I found manually declares the string as unicode and the pattern with the re.UNICODE flag so actual letters from different languages are detected.
# -*- coding: utf-8 -*-
import re
pattern = re.compile("[^\w\d]",re.UNICODE)
n_uni = 'ähm whatßs äüöp ×äØü'
uni = u'ähm whatßs äüöp ×äØü'
words = pattern.split(n_uni) #doesn't work
u_words = pattern.split(uni) #works
So if I write the string directly in the source and manually define it as Unicode it gives me the desired output while the non-Unicode string gives me just garbage:
"ähm whatßs äüöp äØü" -> unicode
"hm what s ü p ü" -> non-unicode even with some invalid characters
My question is now how do I define the input from a file as Unicode?

My question is now how do I define the input from a file as unicode?
Straight from the docs.
import codecs
f = codecs.open('unicode.rst', encoding='utf-8')
for line in f:
print repr(line)

Related

How to decode this "%E3%83%9C" string in python? [duplicate]

This question already has answers here:
Url decode UTF-8 in Python
(5 answers)
Closed 6 months ago.
So I have the following string
"%E3%83%9C%E3%83%89%E3%82%AB%E3%81%95%E3%82%93"
It actually means this
ボドカさん
This string seems to be encoded in UTF-8 because when I write this in python
encoded_str = b'\xe3\x83\x9c\xe3\x83\x89\xe3\x82\xab\xe3\x81\x95\xe3\x82\x93'
print(encoded_str)
print(encoded_str.decode('utf-8'))
Here is the output I get
b'\xe3\x83\x9c\xe3\x83\x89\xe3\x82\xab\xe3\x81\x95\xe3\x82\x93'
ボドカさん
But now I would like a script that will allow me to decode any string in the initial format and here is my code.
import re
import os
mystr = "%E3%83%9C%E3%83%89%E3%82%AB%E3%81%95%E3%82%93"
mystr = mystr.lower()
mystr = re.sub('%', r'\\x', mystr)
encoded_str = bytes(mystr, "utf-8")
print(mystr)
print(encoded_str)
print(encoded_str.decode('utf-8'))
Output:
\xe3\x83\x9c\xe3\x83\x89\xe3\x82\xab\xe3\x81\x95\xe3\x82\x93
b'\\xe3\\x83\\x9c\\xe3\\x83\\x89\\xe3\\x82\\xab\\xe3\\x81\\x95\\xe3\\x82\\x93'
\xe3\x83\x9c\xe3\x83\x89\xe3\x82\xab\xe3\x81\x95\xe3\x82\x93
I tried so many possibilities but I couldn't find the right way to encode proprely my string like the b'STRING' thing would do. I always get extra \ characters from the encoding process that then spoil the decoding process too.
I tried all the encoding methods existing in python for the bytes() function.
I need help please. Thank you.
Stack overflow banned me for that question lol
mystr = "%E3%83%9C%E3%83%89%E3%82%AB%E3%81%95%E3%82%93"
encoded_str = bytes.fromhex(mystr.replace('%', ''))
print(encoded_str.decode('utf-8'))
Output:
ボドカさん

unicode code points to utf-8 python [duplicate]

This question already has answers here:
Python 2.7: How to convert unicode escapes in a string into actual utf-8 characters
(2 answers)
Closed 5 years ago.
I downloaded tweets in Urdu language. When I read the csv file using pandas in python, the tweet is shown as follows:
Sample tweet text
Unicode code point
I want to convert this into utf-8.
When you are writing the tweet data to a file use .decode('utf-8')
And when you try to read data from that file use .encode('utf-8')
Here I am posting an example:
# -*- coding: utf-8 -*-
string1 = "آکاش کمار"
string2 = string1.decode('utf-8')
string3 = string2.encode('utf-8')
print(string3)

Running Python 2.7 Code With Unicode Characters in Source

I want to run a Python source file that contains unicode (utf-8) characters in the source. I am aware of the fact that this can be done by adding the comment # -*- coding: utf-8 -*- in the beginning. However, I wish to do it without using this method.
One way I could think of was writing the unicode strings in escaped form. For example,
Edit: Updated Source. Added Unicode comments.
# Printing naïve and 男孩
def fxn():
print 'naïve'
print '男孩'
fxn()
becomes
# Printing na\xc3\xafve and \xe7\x94\xb7\xe5\xad\xa9
def fxn():
print 'na\xc3\xafve'
print '\xe7\x94\xb7\xe5\xad\xa9'
fxn()
I have two questions regarding the above method.
How do I convert the first code snippet, using Python, into its equivalent that
follows it? That is, only unicode sequences should be written in
escaped form.
Is the method foolproof considering only unicode (utf-8) characters are used? Is there something that can go wrong?
Your idea is generally sound but will break in Python 3 and will cause a headache when you manipulating and writing your strings in Python 2.
It's a good idea to use Unicode strings, not regular strings when dealing with non-ASCII.
Instead, you can encode your characters as Unicode (not UTF-8) escape sequences in Unicode strings.
u'na\xefve'
u'\u7537\u5b69'
note the u prefix
Your code is now encoding agnostic.
If you only use byte strings, and save your source file encoded as UTF-8, your byte strings will contain UTF-8-encoded data. No need for the coding statement (although REALLY strange that you don't want to use it...it's just a comment). The coding statement let's Python know the encoding of the source file, so it can decode Unicode strings correctly (u'xxxxx'). If you have no Unicode strings, it doesn't matter.
For your questions, no need to convert to escape codes. If you encode the file as UTF-8, you can use the more readable characters in your byte strings.
FYI, that won't work for Python 3, because byte strings cannot contain non-ASCII in that version.
That said, here's some code that will convert your example as requested. It reads the source assuming it is encoded in UTF-8, then uses a regular expression to locate all non-ASCII characters. It passes them through a conversion function to generate the replacement. This should be safe, since non-ASCII can only be used in string literals and constants in Python 2. Python 3, however, allows non-ASCII in variable names so this wouldn't work there.
import io
import re
def escape(m):
char = m.group(0).encode('utf8')
return ''.join(r'\x{:02x}'.format(ord(b)) for b in char)
with io.open('sample.py',encoding='utf8') as f:
content = f.read()
new_content = re.sub(r'[^\x00-\x7f]',escape,content)
with io.open('sample_new.py','w',encoding='utf8') as f:
f.write(new_content)
Result:
# Printing na\xc3\xafve and \xe7\x94\xb7\xe5\xad\xa9
def fxn():
print 'na\xc3\xafve'
print '\xe7\x94\xb7\xe5\xad\xa9'
fxn()
question 1:
try to use:
print u'naïve'
print u'长者'
question 2:
If you type the sentences by keyboard and Chinese input software, everything should be OK. But if you copy and paste sentence from some web pages, you should consider other encode format such as GBK,GB2312 and GB18030
This snippet of Python 3 should convert your program correctly to work in Python 2.
def convertchar(char): #converts individual characters
if 32<=ord(char)<=126 or char=="\n": return char #if normal character, return it
h=hex(ord(char))[2:]
if ord(char)<256: #if unprintable ASCII
h=" "*(2-len(h))+h
return "\\x"+h
elif ord(char)<65536: #if short unicode
h=" "*(4-len(h))+h
return "\\u"+h
else: #if long unicode
h=" "*(8-len(h))+h
return "\\U"+h
def converttext(text): #converts a chunk of text
newtext=""
for char in text:
newtext+=convertchar(char)
return newtext
def convertfile(oldfilename,newfilename): #converts a file
oldfile=open(oldfilename,"r")
oldtext=oldfile.read()
oldfile.close()
newtext=converttext(oldtext)
newfile=open(newfilename,"w")
newfile.write(newtext)
newfile.close()
convertfile("FILE_TO_BE_CONVERTED","FILE_TO_STORE_OUTPUT")
First a simple remarl: as you are using byte strings in a Python2 script, the # -*- coding: utf-8 -*- has simply no effect. It only helps to convert the source byte string to an unicode string if you had written:
# -*- coding: utf-8 -*-
...
utxt = u'naïve' # source code is the bytestring `na\xc3\xafve'
# but utxt must become the unicode string u'na\xefve'
Simply it might be interpreted by clever editors to automatically use a utf8 charset.
Now for the actual question. Unfortunately, what you are asking for is not really trivial: idenfying in a source file what is in a comment and in a string simply requires a Python parser... And AFAIK, if you use the parser of ast modules you will lose your comments except for docstrings.
But in Python 2, non ASCII characters are only allowed in comments and litteral strings! So you can safely assume that if the source file is a correct Python 2 script containing no litteral unicode string(*), you can safely transform any non ascii character in its Python representation.
A possible Python function reading a raw source file from a file object and writing it after encoding in another file object could be:
def src_encode(infile, outfile):
while True:
c = infile.read(1)
if len(c) < 1: break # stop on end of file
if ord(c) > 127: # transform high characters
c = "\\x{:2x}".format(ord(c))
outfile.write(c)
An nice property is that it works whatever encoding you use, provided the source file is acceptable by a Python interpreter and does not contain high characters in unicode litterals(*), and the converted file will behave exactly the same as the original one...
(*) A problem will arise if you use unicode litterals in an encoding other that Latin1, because the above function will behave as if the file contained the declaration # -*- coding: Latin1 -*-: u'é' will be translated correctly as u'\xe9' if original encoding is latin1 but as u'\xc3\xc9' (not what is expected...) if original encoding is utf8, and I cannot imagine a way to process correctly both litteral byte strings and unicode byte strings without fully parsing the source file...

Declaring encoding in Python [duplicate]

This question already has answers here:
Working with UTF-8 encoding in Python source [duplicate]
(2 answers)
Closed 8 years ago.
I want to split a string in python using this code:
means="a ، b ، c"
lst=means.split("،")
but I get this error message:
SyntaxError: Non-ASCII character '\xd8' in file dict.py on line 2, but no encoding declared; see http://www.python.org/peps/pep-0263.html for details
How do I declare an encoding?
Put:
# -*- coding: UTF-8 -*-
as the first line of the file (or second line if using *nix) and save the file as UTF-8.
If you're using Python 2, use Unicode string literals (u"..."), for example:
means = u"a ، b ، c"
lst = means.split(u"،")
If you're using Python 3, string literals are Unicode already (unless marked as bytestrings b"...").
You need to declare an encoding for your file, as documented here and here.

Python JSON loads/dumps breaks Unicode? [duplicate]

This question already has answers here:
Saving UTF-8 texts with json.dumps as UTF-8, not as a \u escape sequence
(12 answers)
Closed 7 months ago.
Dumping a string that contains unicode characters as json produces weird unicode escape sequences:
text = "⌂⚘いの法嫁"
print(text) # output: ⌂⚘いの法嫁
import json
json_text = json.dumps(text)
print(json_text) # output: "\u2302\u2698\u3044\u306e\u6cd5\u5ac1"
I'd like to get this output instead:
"⌂⚘いの法嫁"
How can I dump unicode characters as characters instead of escape sequences?
Call json.dumps with ensure_ascii=False:
json_string = json.dumps(json_dict, ensure_ascii=False)
On Python 2, the return value will be unicode instead of str, so you might want to encode it before doing anything else with it.

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