lquery
Try bring C# linq to python
The library is a demo, not for production (yet).
Compare with Others
Different between lquery and others (linq for python like asq):
lquery try convert func (from bytecode) to SQL and query from database process.
Compare with CSharp
For C#:
IQueryable<?> query = null;
var items = query.Where(z => z.Name == 's').Select(z => z.Value).ToList();So for python:
query: Queryable = None;
expr = query.where(z => z.name == 's').select(z => z.value).to_list();for in-memory iterable
from lquery import enumerable
query: Queryable = enumerable([1, 2, 3])
# then query itfor mongodb
from lquery.extras.mongodb import MongoDbQuery
collection = # get a collection from pymongo
query: Queryable = MongoDbQuery(collection)
# then query itlinq APIs
-
to_memory- same asAsEnumerable()from C# whereselectselect_manytakeskip
read more examples from unittests.
Others
print reduce info
Print reduce info is easy way to check what query will compile to SQL.
code example:
>>> from lquery.extras.mongodb import MongoDbQuery
>>> mongo_query = MongoDbQuery(None)
>>> reduce_info = mongo_query\
... .where(lambda x: (x['size']['h'] == 14) & (x['size']['uom'] == 'cm'))\
... .skip(1)\
... .where(lambda x: x['size']['w'] > 15)\
... .get_reduce_info()
>>> reduce_info.print()
reduce info of:
Queryable()
.where(<function <lambda> at 0x0000025DBC661EA0>)
.skip(1)
.where(<function <lambda> at 0x0000025DBE957840>)
=>
[SQL] where(<function <lambda> at 0x0000025DBC661EA0>)
[SQL] skip(1)
[MEM] where(<function <lambda> at 0x0000025DBE957840>)you can see the 1st where() and 1st skip() was success compile to SQL, and 2nd where() only work inside python process.
