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Examples

Serialization

Dumping one object to a file

Use dump to serialize a json object to a file.

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from msglc import dump

data = {"a": [1, 2, 3], "b": {"c": 4, "d": 5, "e": [0x221548313] * 10}}
dump("data.msg", data)

Combining several files

Use combine to combine several serialized files together. The combined files can be further combined.

Combine as dict

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from msglc import dump, combine, FileInfo
from msglc.reader import LazyReader

dump("dict.msg", {str(v): v for v in range(1000)})
dump("list.msg", [float(v) for v in range(1000)])

combine("combined.msg", [FileInfo("dict.msg", "dict"), FileInfo("list.msg", "list")])
# support recursively combining files
# ...

# the combined file uses a dict layout
# { 'dict' : {'1':1,'2':2,...}, 'list' : [1.0,2.0,3.0,...] }
# so one can read it as follows, details in coming section
with LazyReader("combined.msg") as reader:
    assert reader['dict/101'] == 101  # also reader['dict'][101]
    assert reader['list/101'] == 101.0  # also reader['list'][101]

Combine as list

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from msglc import dump, combine, FileInfo
from msglc.reader import LazyReader

dump("dict.msg", {str(v): v for v in range(1000)})
dump("list.msg", [float(v) for v in range(1000)])

combine("combined.msg", [FileInfo("dict.msg"), FileInfo("list.msg")])
# support recursively combining files
# ...

# the combined file uses a list layout
# [ {'1':1,'2':2,...}, [1.0,2.0,3.0,...] ]
# so one can read it as follows, details in coming section
with LazyReader("combined.msg") as reader:
    assert reader['0/101'] == 101  # also reader[0][101]
    assert reader['1/101'] == 101.0  # also reader[1][101]

Deserialization

Use LazyReader to read a file.

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from msglc.reader import LazyReader, to_obj

with LazyReader("data.msg") as reader:
    data = reader.read()  # return a LazyDict, LazyList, dict, list or primitive value
    data = reader["b/c"]  # subscriptable if the actual data is subscriptable
    # data = reader[2:]  # also support slicing if its underlying data is list compatible
    data = reader.read("b/c")  # or provide a path to visit a particular node
    print(data)  # 4
    b_dict = reader.read("b")
    print(b_dict.__class__)  # <class 'msglc.reader.LazyDict'>
    for k, v in b_dict.items():  # dict compatible
        if k != "e":
            print(k, v)  # c 4, d 5
    b_json = to_obj(b_dict)  # ensure plain dict