我对Reply很感兴趣，因为我正在寻找一个工具，它可以推断出一个匹配字符串的正则表达式。用help检查rexpy.extract，看起来它“可能”是我想要的。

extract(examples, tag=False, encoding=None, as_object=False, extra_letters=None, full_escape=False, remove_empties=False, strip=False, variableLengthFrags=False, max_patterns=None, min_diff_strings_per_pattern=1, min_strings_per_pattern=1, size=None, seed=None, dialect='portable', verbose=0)
    Extract regular expression(s) from examples and return them.
    
    Normally, examples should be unicode (i.e. ``str`` in Python3,
    and ``unicode`` in Python2). However, encoded strings can be
    passed in provided the encoding is specified.
    
    Results will always be unicode.
    
    If as_object is set, the extractor object is returned,
    with results in .results.rex; otherwise, a list of regular
    expressions, as unicode strings is returned.

我试了一个例子：

>>> from tdda import rexpy
>>> s = 'andrew.gelman@statistics.com'
>>> rexpy.extract(s)
['^[.@]$', '^[a-z]$']

我期望类似于['^[a-z].[a-z]@[a-z].[a-z]$']而不是['^[.@]$', '^[a-z]$']。提取器是否只是告诉我特殊符号'.'和'@'在字符串中的“某处”使用？