python - Mongoengine - 使用 icontains 与所有

Question

我见过this question但它并没有回答我的问题，甚至没有很好地提出它。

我认为最好用一个例子来解释这一点:

class Blah(Document):
    someList = ListField(StringField())

Blah.drop_collection()

Blah(someList=['lop', 'glob', 'hat']).save()
Blah(someList=['hello', 'kitty']).save()

# One of these should match the first entry
print(Blah.objects(someList__icontains__all=['Lo']).count())
print(Blah.objects(someList__all__icontains=['Lo']).count())

我假设这会打印 1, 0 或 0, 1 (或奇迹般地 1, 1)，但它却给出

0
Traceback (most recent call last):
  File "metst.py", line 14, in <module>
    print(Blah.objects(someList__all__icontains=['lO']).count())
  File "/home/blah/.pythonbrew/pythons/Python-3.1.4/lib/python3.1/site-packages/mongoengine/queryset.py", line 1034, in count
    return self._cursor.count(with_limit_and_skip=True)
  File "/home/blah/.pythonbrew/pythons/Python-3.1.4/lib/python3.1/site-packages/mongoengine/queryset.py", line 608, in _cursor
    self._cursor_obj = self._collection.find(self._query,
  File "/home/blah/.pythonbrew/pythons/Python-3.1.4/lib/python3.1/site-packages/mongoengine/queryset.py", line 390, in _query
    self._mongo_query = self._query_obj.to_query(self._document)
  File "/home/blah/.pythonbrew/pythons/Python-3.1.4/lib/python3.1/site-packages/mongoengine/queryset.py", line 213, in to_query
    query = query.accept(QueryCompilerVisitor(document))
  File "/home/blah/.pythonbrew/pythons/Python-3.1.4/lib/python3.1/site-packages/mongoengine/queryset.py", line 278, in accept
    return visitor.visit_query(self)
  File "/home/blah/.pythonbrew/pythons/Python-3.1.4/lib/python3.1/site-packages/mongoengine/queryset.py", line 170, in visit_query
    return QuerySet._transform_query(self.document, **query.query)
  File "/home/blah/.pythonbrew/pythons/Python-3.1.4/lib/python3.1/site-packages/mongoengine/queryset.py", line 755, in _transform_query
    value = field.prepare_query_value(op, value)
  File "/home/blah/.pythonbrew/pythons/Python-3.1.4/lib/python3.1/site-packages/mongoengine/fields.py", line 594, in prepare_query_value
    return self.field.prepare_query_value(op, value)
  File "/home/blah/.pythonbrew/pythons/Python-3.1.4/lib/python3.1/site-packages/mongoengine/fields.py", line 95, in prepare_query_value
    value = re.escape(value)
  File "/home/blah/.pythonbrew/pythons/Python-3.1.4/lib/python3.1/re.py", line 246, in escape
    return bytes(s)
TypeError: 'str' object cannot be interpreted as an integer

这两个查询都不起作用!

MongoEngine是否支持使用icontains和all进行搜索的某种方式？或者有什么办法可以解决这个问题？

注意:我想使用 MongoEngine，而不是 PyMongo。

编辑:Python 2.7.3 也存在同样的问题。

Answer 1

截至目前(版本 0.8.0)，执行此操作的唯一方法是使用 __raw__ 查询，可能与 re.compile() 结合使用。就像这样:

import re

input_list = ['Lo']
converted_list = [re.compile(q, re.I) for q in input_list]

print(Blah.objects(__raw__={"someList": {"$all": converted_list}}).count())

<小时/>

目前 mongoengine 中还没有办法将 all 和 icontains 结合起来，唯一可以与其他运算符一起使用的运算符是 not 。 the docs 中巧妙地提到了这一点。 ，正如其中所说:

not – negate a standard check, may be used before other operators (e.g. Q(age_not_mod=5))

_强调我的

但它并没有说你不能用其他运算符来做到这一点，实际上就是这样。

<小时/>

您可以通过查看源代码来确认此行为:

版本 0.8.0+(in module - mongoengine/queryset/transform.py - 第 42-48 行):

if parts[-1] in MATCH_OPERATORS:
    op = parts.pop()

negate = False
if parts[-1] == 'not':
    parts.pop()
    negate = True

在旧版本中，可以在 _transform_query 方法中的 mongoengine/queryset.py 中看到上述行。