I have trouble with Emacs+Python 2.7.1+Encoding. According to PEP 0263, Python uses the same declaration of source encoding as emacs does.
There is no problem when I start my Python source code script with the following encoding tag:
#!/usr/bin/python
# -*- mode=python; encoding:us-ascii -*-
But when I add a line ending mode to my encoding such as in:
#!/usr/bin/python
# -*- mode=python; encoding:us-ascii-unix -*-
Emacs still acepts my encoding information, but I get the following error from Python when executing my script:
File "./unicode.py", line 2
SyntaxError: encoding problem: with BOM
Is there a way to tell Emacs about the line ending I want to use and at the same time tell Python about the source file encoding?
You can write two blocks: one that is parsed only by the interpreter, and one that is only parsed by Emacs:
#!/usr/bin/python
# coding: us-ascii
print "Hello World"
# Local Variables:
# mode: python
# coding: us-ascii-unix
# End:
Note that (1) us-ascii is the default in Python 2.x; and (2) Emacs is usually able to determine the line ending convention automatically; so you might be able to get along without declaring anything.
Related
I want to run my code on terminal but it shows me this error :
SyntaxError: Non-ASCII character '\xd8' in file streaming.py on line
72, but no encoding declared; see http://python.org/dev/peps/pep-0263/
for detail
I tried to encode the Arabic string using this :
# -*- coding: utf-8 -*-
st = 'المملكة العربية السعودية'.encode('utf-8')
It's very important for me to run it on the terminal so I can't use IDLE.
The problem is since you are directly pasting your characters in to a python file, the interpreter (Python 2) attempts to read them as ASCII (even before you encode, it needs to define the literal), which is illegal. What you want is a unicode literal if pasting non-ASCII bytes:
x=u'المملكة العربية السعودية' #Or whatever the corresponding bytes are
print x.encode('utf-8')
You can also try to set the entire source file to be read as utf-8:
#/usr/bin/python
# -*- coding: utf-8 -*-
and don't forget to make it run-able, and lastly, you can import the future from Python 3:
from __future__ import unicode_literal
at the top of the file, so string literals by default are utf-8. Note that \xd8 appears as phi in my terminal, so make sure the encoding is correct.
Say I have a function:
def NewFunction():
return '£'
I want to print some stuff with a pound sign in front of it and it prints an error when I try to run this program, this error message is displayed:
SyntaxError: Non-ASCII character '\xa3' in file 'blah' but no encoding declared;
see http://www.python.org/peps/pep-0263.html for details
Can anyone inform me how I can include a pound sign in my return function? I'm basically using it in a class and it's within the '__str__' part that the pound sign is included.
I'd recommend reading that PEP the error gives you. The problem is that your code is trying to use the ASCII encoding, but the pound symbol is not an ASCII character. Try using UTF-8 encoding. You can start by putting # -*- coding: utf-8 -*- at the top of your .py file. To get more advanced, you can also define encodings on a string by string basis in your code. However, if you are trying to put the pound sign literal in to your code, you'll need an encoding that supports it for the entire file.
Adding the following two lines at the top of my .py script worked for me (first line was necessary):
#!/usr/bin/env python
# -*- coding: utf-8 -*-
First add the # -*- coding: utf-8 -*- line to the beginning of the file and then use u'foo' for all your non-ASCII unicode data:
def NewFunction():
return u'£'
or use the magic available since Python 2.6 to make it automatic:
from __future__ import unicode_literals
The error message tells you exactly what's wrong. The Python interpreter needs to know the encoding of the non-ASCII character.
If you want to return U+00A3 then you can say
return u'\u00a3'
which represents this character in pure ASCII by way of a Unicode escape sequence. If you want to return a byte string containing the literal byte 0xA3, that's
return b'\xa3'
(where in Python 2 the b is implicit; but explicit is better than implicit).
The linked PEP in the error message instructs you exactly how to tell Python "this file is not pure ASCII; here's the encoding I'm using". If the encoding is UTF-8, that would be
# coding=utf-8
or the Emacs-compatible
# -*- encoding: utf-8 -*-
If you don't know which encoding your editor uses to save this file, examine it with something like a hex editor and some googling. The Stack Overflow character-encoding tag has a tag info page with more information and some troubleshooting tips.
In so many words, outside of the 7-bit ASCII range (0x00-0x7F), Python can't and mustn't guess what string a sequence of bytes represents. https://tripleee.github.io/8bit#a3 shows 21 possible interpretations for the byte 0xA3 and that's only from the legacy 8-bit encodings; but it could also very well be the first byte of a multi-byte encoding. But in fact, I would guess you are actually using Latin-1, so you should have
# coding: latin-1
as the first or second line of your source file. Anyway, without knowledge of which character the byte is supposed to represent, a human would not be able to guess this, either.
A caveat: coding: latin-1 will definitely remove the error message (because there are no byte sequences which are not technically permitted in this encoding), but might produce completely the wrong result when the code is interpreted if the actual encoding is something else. You really have to know the encoding of the file with complete certainty when you declare the encoding.
Adding the following two lines in the script solved the issue for me.
# !/usr/bin/python
# coding=utf-8
Hope it helps !
You're probably trying to run Python 3 file with Python 2 interpreter. Currently (as of 2019), python command defaults to Python 2 when both versions are installed, on Windows and most Linux distributions.
But in case you're indeed working on a Python 2 script, a not yet mentioned on this page solution is to resave the file in UTF-8+BOM encoding, that will add three special bytes to the start of the file, they will explicitly inform the Python interpreter (and your text editor) about the file encoding.
I'm writing python code on eclipse and whenver I use hebrew characters I get the following syntax error:
SyntaxError: Non-ASCII character '\xfa' in file ... on line 66, but no encoding declared; see http://www.python.org/peps/pep-0263.html for details
How do I declare unicode/utf-8 encoding?
I tried adding
-*- coding: Unicode -*-
or
-*- coding: utf-8 -*-
in the commented section in the beginnning of the py file. It didn't work.
I'm running eclipse with pydev, python 2.6 on windows 7.
I tried it also and here is my conclusion:
You should add
# -*- coding: utf-8 -*-
at the very first line in your file.
And yes, I work with windows...
If I got it right, you are missing the #
Ensure that the encoding the editor is using to enter data matches the declared encoding in the file metadata.
This isn't something unique to Eclipse or Python; it applies to all character data formats and text editors.
Python has a number of options for dealing with string literals in both the str and unicode types via escape sequences. I believe there were changes to string literals between Python 2 and 3.
Python 2.7 string literals
Python 3.2 string literals
I had the same thing and it was because I'd tried to do:
a='言語版の記事'
When I should have done:
a=u'言語版の記事'
I think it's python/pydev complaining when trying to parse the source, rather than eclipse as such.
"Unicode" is certainly wrong, and \xfa is not UTF-8. Figure out which encoding is actually being used and declare that instead.
Python recognizes the following as instruction which defines file's encoding:
# -*- coding: utf-8 -*-
I definitely saw this kind of instructions before (-*- var: value -*-). Where does it come from? What is the full specification, e.g. can the value include spaces, special symbols, newlines, even -*- itself?
My program will be writing plain text files and I'd like to include some metadata in them using this format.
This way of specifying the encoding of a Python file comes from PEP 0263 - Defining Python Source Code Encodings.
It is also recognized by GNU Emacs (see Python Language Reference, 2.1.4 Encoding declarations), though I don't know if it was the first program to use that syntax.
# -*- coding: utf-8 -*- is a Python 2 thing.
In Python 3.0+ the default encoding of source files is already UTF-8 so you can safely delete that line, because unless it says something other than some variation of "utf-8", it has no effect. See Should I use encoding declaration in Python 3?
pyupgrade is a tool you can run on your code to remove those comments and other useless leftovers from Python 2, like having all your classes inherit from object.
This is so called file local variables, that are understood by Emacs and set correspondingly. See corresponding section in Emacs manual - you can define them either in header or in footer of file
In PyCharm, I'd leave it out. It turns off the UTF-8 indicator at the bottom with a warning that the encoding is hard-coded. Don't think you need the PyCharm comment mentioned above.
PEP 263 defines how to declare Python source code encoding.
Normally, the first 2 lines of a Python file should start with:
#!/usr/bin/python
# -*- coding: <encoding name> -*-
But I have seen a lot of files starting with:
#!/usr/bin/python
# -*- encoding: <encoding name> -*-
=> encoding instead of coding.
So what is the correct way of declaring the file encoding?
Is encoding permitted because the regex used is lazy? Or is it just another form of declaring the file encoding?
I'm asking this question because the PEP does not talk about encoding, it just talks about coding.
Check the docs here:
"If a comment in the first or second line of the Python script matches the regular expression coding[=:]\s*([-\w.]+), this comment is processed as an encoding declaration"
"The recommended forms of this expression are
# -*- coding: <encoding-name> -*-
which is recognized also by GNU Emacs, and
# vim:fileencoding=<encoding-name>
which is recognized by Bram Moolenaar’s VIM."
So, you can put pretty much anything before the "coding" part, but stick to "coding" (with no prefix) if you want to be 100% python-docs-recommendation-compatible.
More specifically, you need to use whatever is recognized by Python and the specific editing software you use (if it needs/accepts anything at all). E.g. the coding form is recognized (out of the box) by GNU Emacs but not Vim (yes, without a universal agreement, it's essentially a turf war).
Just copy paste below statement on the top of your program.It will solve character encoding problems
#!/usr/bin/env python
# -*- coding: utf-8 -*-
PEP 263:
the first or second line must match
the regular
expression "coding[:=]\s*([-\w.]+)"
So, "encoding: UTF-8" matches.
PEP provides some examples:
#!/usr/bin/python
# vim: set fileencoding=<encoding name> :
# This Python file uses the following encoding: utf-8
import os, sys
As of today — June 2018
PEP 263 itself mentions the regex it follows:
To define a source code encoding, a magic comment must be placed into
the source files either as first or second line in the file, such as:
# coding=<encoding name>
or (using formats recognized by popular editors):
#!/usr/bin/python
# -*- coding: <encoding name> -*-
or:
#!/usr/bin/python
# vim: set fileencoding=<encoding name> :
More precisely, the first or second line must match the following regular expression:
^[ \t\f]*#.*?coding[:=][ \t]*([-_.a-zA-Z0-9]+)
So, as already summed up by other answers, it'll match coding with any prefix, but if you'd like to be as PEP-compliant as it gets (even though, as far as I can tell, using encoding instead of coding does not violate PEP 263 in any way) — stick with 'plain' coding, with no prefixes.
If I'm not mistaken, the original proposal for source file encodings was to use a regular expression for the first couple of lines, which would allow both.
I think the regex was something along the lines of coding: followed by something.
I found this: http://www.python.org/dev/peps/pep-0263/
Which is the original proposal, but I can't seem to find the final spec stating exactly what they did.
I've certainly used encoding: to great effect, so obviously that works.
Try changing to something completely different, like duhcoding: ... to see if that works just as well.
I suspect it is similar to Ruby - either method is okay.
This is largely because different text editors use different methods (ie, these two) of marking encoding.
With Ruby, as long as the first, or second if there is a shebang line contains a string that matches:
coding: encoding-name
and ignoring any whitespace and other fluff on those lines. (It can often be a = instead of :, too).