我如何 .decode('string-escape') 在 Python3 中？
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how do I .decode('string-escape') in Python3?
提问by vy32
I have some escaped strings that need to be unescaped. I'd like to do this in Python.
我有一些需要转义的转义字符串。我想在 Python 中做到这一点。
For example, in python2.7 I can do this:
例如，在 python2.7 中，我可以这样做：
>>> "\123omething special".decode('string-escape')
'Something special'
>>>
How do I do it in Python3? This doesn't work:
我如何在 Python3 中做到这一点？这不起作用：
>>> b"\123omething special".decode('string-escape')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
LookupError: unknown encoding: string-escape
>>>
My goal is to be abel to take a string like this:
我的目标是成为 abel 接受这样的字符串：
s"[email protected]"
0udef string_escape(s, encoding='utf-8'):
return (s.encode('latin1') # To bytes, required by 'unicode-escape'
.decode('unicode-escape') # Perform the actual octal-escaping decode
.encode('latin1') # 1:1 mapping back to bytes
.decode(encoding)) # Decode original encoding
0p>>> string_escape('\123omething special')
'Something special'
>>> string_escape(r's>>> b"\123omething special".decode('unicode_escape')
0u>>> value = b's\000u\000p\000p\000o\000r\000t\000@\000p\000s\000i\000l\000o\000c\000.\000c\000o\000m\000'
>>> value.decode('unicode_escape').encode('latin1') # convert to bytes
b's\x00u\x00p\x00p\x00o\x00r\x00t\x00@\x00p\x00s\x00i\x00l\x00o\x00c\x00.\x00c\x00o\x00m\x00'
>>> _.decode('utf-16-le') # decode from UTF-16-LE
'[email protected]'
0pdef unescape(text):
regex = re.compile(b'\\(\\|[0-7]{1,3}|x.[0-9a-f]?|[\'"abfnrt]|.|$)')
def replace(m):
b = m.group(1)
if len(b) == 0:
raise ValueError("Invalid character escape: '\'.")
i = b[0]
if i == 120:
v = int(b[1:], 16)
elif 48 <= i <= 55:
v = int(b, 8)
elif i == 34: return b'"'
elif i == 39: return b"'"
elif i == 92: return b'\'
elif i == 97: return b'\a'
elif i == 98: return b'\b'
elif i == 102: return b'\f'
elif i == 110: return b'\n'
elif i == 114: return b'\r'
elif i == 116: return b'\t'
else:
s = b.decode('ascii')
raise UnicodeDecodeError(
'stringescape', text, m.start(), m.end(), "Invalid escape: %r" % s
)
return bytes((v, ))
result = regex.sub(replace, text)
0p>>> import codecs
>>> codecs.escape_decode(b"ab\xff")
(b'ab\xff', 6)
>>> codecs.escape_encode(b"ab\xff")
(b'ab\xff', 3)
0o>>> value = b's\000u\000p\000p\000o\000r\000t\000@\000p\000s\000i\000l\000o\000c\000.\000c\000o\000m\000'
>>> codecs.escape_decode(value)[0]
b's\x00u\x00p\x00p\x00o\x00r\x00t\x00@\x00p\x00s\x00i\x00l\x00o\x00c\x00.\x00c\x00o\x00m\x00'
0rPy2: my_input.decode('string_escape')
Py3: bytes(my_input.decode('unicode_escape'), 'latin1')
0tdef string_escape(my_bytes):
return bytes(my_bytes.decode('unicode_escape'), 'latin1')
0@'
r'##代码##0p##代码##0s##代码##0i##代码##0l##代码##0o##代码##0c##代码##0.##代码##0c##代码##0o##代码##0m##代码##0',
'utf-16-le')
'[email protected]'
0p##代码##0o##代码##0r##代码##0t##代码##0@##代码##0p##代码##0s##代码##0i##代码##0l##代码##0o##代码##0c##代码##0.##代码##0c##代码##0o##代码##0m##代码##0
And turn it into:
并将其变成：
##代码##After I do the conversion, I'll probe to see if the string I have is encoded in UTF-8 or UTF-16.
完成转换后，我将探查我拥有的字符串是用 UTF-8 还是 UTF-16 编码的。
采纳答案by MestreLion
If you want str-to-strdecoding of escape sequences, so both input and output are Unicode:
如果你想str-to- str解码转义序列，那么输入和输出都是 Unicode：
##代码##Testing:
测试：
##代码##回答by Martijn Pieters
You'll have to use unicode_escapeinstead:
你必须unicode_escape改用：
If you startwith a strobject instead (equivalent to the python 2.7 unicode) you'll need to encode to bytes first, then decode with unicode_escape.
如果你开始使用str对象，而不是（相当于Python 2.7版的Unicode），您需要编码的字节先，然后用解码unicode_escape。
If you need bytes as end result, you'll have to encode again to a suitable encoding (.encode('latin1')for example, if you need to preserve literal byte values; the first 256 Unicode code points map 1-on-1).
如果您需要字节作为最终结果，则必须再次编码.encode('latin1')为合适的编码（例如，如果您需要保留文字字节值；前 256 个 Unicode 代码点映射一对一）。
Your example is actually UTF-16 data with escapes. Decode from unicode_escape, back to latin1to preserve the bytes, then from utf-16-le(UTF 16 little endian without BOM):
您的示例实际上是带有转义符的 UTF-16 数据。解码 from unicode_escape, back tolatin1以保留字节，然后 from utf-16-le(UTF 16 little endian without BOM):
回答by malthe
You can't use unicode_escapeon byte strings (or rather, you can, but it doesn't always return the same thing as string_escapedoes on Python 2) – beware!
你不能unicode_escape在字节字符串上使用（或者更确切地说，你可以，但它并不总是像string_escape在 Python 2 上那样返回相同的东西）——当心！
This function implements string_escapeusing a regular expression and custom replacement logic.
此函数string_escape使用正则表达式和自定义替换逻辑来实现。
回答by Nathaniel J. Smith
The old "string-escape" codec maps bytestrings to bytestrings, and there's been a lot of debate about what to do with such codecs, so it isn't currently available through the standard encode/decode interfaces.
旧的“字符串转义”编解码器将字节串映射到字节串，关于如何处理此类编解码器存在很多争论，因此目前无法通过标准编码/解码接口使用它。
BUT, the code is still there in the C-API (as PyBytes_En/DecodeEscape), and this is still exposed to Python via the undocumented codecs.escape_encodeand codecs.escape_decode.
但是，代码仍然存在于 C-API 中（作为PyBytes_En/DecodeEscape），并且它仍然通过未记录的codecs.escape_encode和codecs.escape_decode.
These functions return the transformed bytesobject, plus a number indicating how many bytes were processed... you can just ignore the latter.
这些函数返回转换后的bytes对象，加上一个表示处理了多少字节的数字……你可以忽略后者。
回答by guettli
At least in my case this was equivalent:
至少在我的情况下，这是等效的：
##代码##convertutils.py:
转换工具.py：
##代码##