There are multiple serialization formats out there ...
... and great packages to use them.
But they all have a different API and switching among them is not so
simple as it should be. Serialize helps you to do it, including dealing
with custom classes. Let's dump a dict using the pickle format:
>>> from serialize import dumps, loads
>>> dumps(dict(answer=42), fmt='pickle')
b'\x80\x04\x95\x0f\x00\x00\x00\x00\x00\x00\x00}\x94\x8c\x06answer\x94K*s.'
>>> loads(_, fmt='pickle')
{'answer': 42}And here comes the cool thing, you can just change the serialization format without having to learn a new API. Let's now dump it using msgpack:
>>> dumps(dict(answer=42), fmt='msgpack')
b'\x81\xa6answer*'
>>> loads(_, fmt='msgpack')
{'answer': 42}Serialize currently support 8 different formats:
- bson
- dill
- json (builtin or with simplejson package),
- msgpack
- phpserialize
- pickle
- serpent
- yaml
Serialize does not implement these formats but rather relies on established, well tested packages. If they are installed, serialize will use them.
Serialize allows you to use them all with the same API!
You can also use the dump and load to write directly to file-like
object:
>>> from serialize import dump, load
>>> with open('output.yaml', 'wb') as fp:
... dump(dict(answer=42), fp, fmt='yaml')
>>> with open('output.yaml', 'rb') as fp:
... load(fp, fmt='yaml')
{'answer': 42}or use directly the filename and the format will be inferred:
>>> dump(dict(answer=42), 'output.yaml')
>>> load('output.yaml')
{'answer': 42}A very common case is to dump and load objects from custom classes such as:
>>> class User:
... def __init__(self, name, age):
... self.name = name
... self.age = age
...
>>> john = User('John Smith', 27)But some serialization packages do not support this important feature and the rest usually have very different API between them. Serialize provides you a common, simple interface for this. You just need to define a function that is able to convert the object to an instance of a builtin type and the converse:
>>> from serialize import register_class
>>> def user_to_builtin(u):
... return (u.name, u.age)
...
>>> def user_from_builtin(c):
... return User(c[0], c[1])
...
>>> register_class(User, user_to_builtin, user_from_builtin)And that's all. You can then use it directly without any hassle:
>>> dumps(john, fmt='bson')
b"x\x00\x00\x00\x03__bson_follow__\x00b\x00\x00\x00\x02__class_name__\x00\x1b\x00\x00\x00<class 'test_readme.User'>\x00\x04__dumped_obj__\x00\x1e\x00\x00\x00\x020\x00\x0b\x00\x00\x00John Smith\x00\x101\x00\x1b\x00\x00\x00\x00\x00\x00"
ain__.Username'>\x00\x00\x00"
>>> v = loads(_, fmt='bson')
>>> v.name
'John Smith'
>>> v.age
27Enjoy!