我正在使用在网络上找到的经过修改的库来解析.stl文件。到目前为止,在非Anaconda Python 3.5.2中,它的运行非常出色。我最近不得不升级到Anaconda Python3.7.4。以下行在3.5中工作正常,但在3.7.4中引发异常]
re.compile(r'[-+]?[0-9]*\.?[0-9]+(\e[-+]?[0-9]+)?')
这是什么原因?例外是:
---------------------------------------------------------------------------
error Traceback (most recent call last)
<ipython-input-2-08df04adea1a> in <module>
----> 1 re.compile(r'[-+]?[0-9]*\.?[0-9]+(\e[-+]?[0-9]+)?')
~/anaconda3/lib/python3.7/re.py in compile(pattern, flags)
232 def compile(pattern, flags=0):
233 "Compile a regular expression pattern, returning a Pattern object."
--> 234 return _compile(pattern, flags)
235
236 def purge():
~/anaconda3/lib/python3.7/re.py in _compile(pattern, flags)
284 if not sre_compile.isstring(pattern):
285 raise TypeError("first argument must be string or compiled pattern")
--> 286 p = sre_compile.compile(pattern, flags)
287 if not (flags & DEBUG):
288 if len(_cache) >= _MAXCACHE:
~/anaconda3/lib/python3.7/sre_compile.py in compile(p, flags)
762 if isstring(p):
763 pattern = p
--> 764 p = sre_parse.parse(p, flags)
765 else:
766 pattern = None
~/anaconda3/lib/python3.7/sre_parse.py in parse(str, flags, pattern)
928
929 try:
--> 930 p = _parse_sub(source, pattern, flags & SRE_FLAG_VERBOSE, 0)
931 except Verbose:
932 # the VERBOSE flag was switched on inside the pattern. to be
~/anaconda3/lib/python3.7/sre_parse.py in _parse_sub(source, state, verbose, nested)
424 while True:
425 itemsappend(_parse(source, state, verbose, nested + 1,
--> 426 not nested and not items))
427 if not sourcematch("|"):
428 break
~/anaconda3/lib/python3.7/sre_parse.py in _parse(source, state, verbose, nested, first)
814 sub_verbose = ((verbose or (add_flags & SRE_FLAG_VERBOSE)) and
815 not (del_flags & SRE_FLAG_VERBOSE))
--> 816 p = _parse_sub(source, state, sub_verbose, nested + 1)
817 if not source.match(")"):
818 raise source.error("missing ), unterminated subpattern",
~/anaconda3/lib/python3.7/sre_parse.py in _parse_sub(source, state, verbose, nested)
424 while True:
425 itemsappend(_parse(source, state, verbose, nested + 1,
--> 426 not nested and not items))
427 if not sourcematch("|"):
428 break
~/anaconda3/lib/python3.7/sre_parse.py in _parse(source, state, verbose, nested, first)
505
506 if this[0] == "\\":
--> 507 code = _escape(source, this, state)
508 subpatternappend(code)
509
~/anaconda3/lib/python3.7/sre_parse.py in _escape(source, escape, state)
400 if len(escape) == 2:
401 if c in ASCIILETTERS:
--> 402 raise source.error("bad escape %s" % escape, len(escape))
403 return LITERAL, ord(escape[1])
404 except ValueError:
error: bad escape \e at position 21
您遇到的问题是由于您添加了\e
的转义序列。将其更改为e
将解决您的问题。
所以从python 3.5.2升级到python 3.7.4之后为什么会发生这种情况?
[非常感谢Wiktor在this question下的注释中指出了正确的方向,指出了这一点。根据What's new in Python 3.6 - Deprecated Python behavior:
现在不是有效的转义序列的反斜杠字符对产生一个
DeprecationWarning
。虽然这最终会变成SyntaxError
,不适用于多个Python版本。