This package bundles some of the best Python serialization libraries into one standalone package, with a high-level API that makes it easy to write code that's correct across platforms and Pythons. This allows us to provide all the serialization utilities we need in a single binary wheel. Currently supports JSON, JSONL, MessagePack, Pickle and YAML.
Serialization is hard, especially across Python versions and multiple platforms.
After dealing with many subtle bugs over the years (encodings, locales, large
files) our libraries like spaCy and
Prodigy had steadily grown a number of utility functions to
wrap the multiple serialization formats we need to support (especially json
,
msgpack
and pickle
). These wrapping functions ended up duplicated across our
codebases, so we wanted to put them in one place.
At the same time, we noticed that having a lot of small dependencies was making
maintenance harder, and making installation slower. To solve this, we've made
srsly
standalone, by including the component packages directly within it. This
way we can provide all the serialization utilities we need in a single binary
wheel.
srsly
currently includes forks of the following packages:
ujson
msgpack
msgpack-numpy
cloudpickle
ruamel.yaml
(without unsafe implementations!)
⚠️ Note thatv2.x
is only compatible with Python 3.6+. For 2.7+ compatibility, usev1.x
.
srsly
can be installed from pip. Before installing, make sure that your pip
,
setuptools
and wheel
are up to date.
python -m pip install -U pip setuptools wheel
python -m pip install srsly
Or from conda via conda-forge:
conda install -c conda-forge srsly
Alternatively, you can also compile the library from source. You'll need to make sure that you have a development environment with a Python distribution including header files, a compiler (XCode command-line tools on macOS / OS X or Visual C++ build tools on Windows), pip and git installed.
Install from source:
# clone the repo
git clone https://github.com/explosion/srsly
cd srsly
# create a virtual environment
python -m venv .env
source .env/bin/activate
# update pip
python -m pip install -U pip setuptools wheel
# compile and install from source
python -m pip install .
For developers, install requirements separately and then install in editable mode without build isolation:
# install in editable mode
python -m pip install -r requirements.txt
python -m pip install --no-build-isolation --editable .
# run test suite
python -m pytest --pyargs srsly
📦 The underlying module is exposed via
srsly.ujson
. However, we normally interact with it via the utility functions only.
Serialize an object to a JSON string. Falls back to json
if sort_keys=True
is used (until it's fixed in ujson
).
data = {"foo": "bar", "baz": 123}
json_string = srsly.json_dumps(data)
Argument | Type | Description |
---|---|---|
data |
- | The JSON-serializable data to output. |
indent |
int | Number of spaces used to indent JSON. Defaults to 0 . |
sort_keys |
bool | Sort dictionary keys. Defaults to False . |
RETURNS | str | The serialized string. |
Deserialize unicode or bytes to a Python object.
data = '{"foo": "bar", "baz": 123}'
obj = srsly.json_loads(data)
Argument | Type | Description |
---|---|---|
data |
str / bytes | The data to deserialize. |
RETURNS | - | The deserialized Python object. |
Create a JSON file and dump contents or write to standard output.
data = {"foo": "bar", "baz": 123}
srsly.write_json("/path/to/file.json", data)
Argument | Type | Description |
---|---|---|
path |
str / Path |
The file path or "-" to write to stdout. |
data |
- | The JSON-serializable data to output. |
indent |
int | Number of spaces used to indent JSON. Defaults to 2 . |
Load JSON from a file or standard input.
data = srsly.read_json("/path/to/file.json")
Argument | Type | Description |
---|---|---|
path |
str / Path |
The file path or "-" to read from stdin. |
RETURNS | dict / list | The loaded JSON content. |
Create a gzipped JSON file and dump contents.
data = {"foo": "bar", "baz": 123}
srsly.write_gzip_json("/path/to/file.json.gz", data)
Argument | Type | Description |
---|---|---|
path |
str / Path |
The file path. |
data |
- | The JSON-serializable data to output. |
indent |
int | Number of spaces used to indent JSON. Defaults to 2 . |
Create a gzipped JSONL file and dump contents.
data = [{"foo": "bar"}, {"baz": 123}]
srsly.write_gzip_json("/path/to/file.jsonl.gz", data)
Argument | Type | Description |
---|---|---|
path |
str / Path |
The file path. |
lines |
- | The JSON-serializable contents of each line. |
append |
bool | Whether or not to append to the location. Appending to .gz files is generally not recommended, as it doesn't allow the algorithm to take advantage of all data when compressing - files may hence be poorly compressed. |
append_new_line |
bool | Whether or not to write a new line before appending to the file. |
Load gzipped JSON from a file.
data = srsly.read_gzip_json("/path/to/file.json.gz")
Argument | Type | Description |
---|---|---|
path |
str / Path |
The file path. |
RETURNS | dict / list | The loaded JSON content. |
Load gzipped JSONL from a file.
data = srsly.read_gzip_jsonl("/path/to/file.jsonl.gz")
Argument | Type | Description |
---|---|---|
path |
str / Path |
The file path. |
RETURNS | dict / list | The loaded JSONL content. |
Create a JSONL file (newline-delimited JSON) and dump contents line by line, or write to standard output.
data = [{"foo": "bar"}, {"baz": 123}]
srsly.write_jsonl("/path/to/file.jsonl", data)
Argument | Type | Description |
---|---|---|
path |
str / Path |
The file path or "-" to write to stdout. |
lines |
iterable | The JSON-serializable lines. |
append |
bool | Append to an existing file. Will open it in "a" mode and insert a newline before writing lines. Defaults to False . |
append_new_line |
bool | Defines whether a new line should first be written when appending to an existing file. Defaults to True . |
Read a JSONL file (newline-delimited JSON) or from JSONL data from standard input and yield contents line by line. Blank lines will always be skipped.
data = srsly.read_jsonl("/path/to/file.jsonl")
Argument | Type | Description |
---|---|---|
path |
str / Path | The file path or "-" to read from stdin. |
skip |
bool | Skip broken lines and don't raise ValueError . Defaults to False . |
YIELDS | - | The loaded JSON contents of each line. |
Check if a Python object is JSON-serializable.
assert srsly.is_json_serializable({"hello": "world"}) is True
assert srsly.is_json_serializable(lambda x: x) is False
Argument | Type | Description |
---|---|---|
obj |
- | The object to check. |
RETURNS | bool | Whether the object is JSON-serializable. |
📦 The underlying module is exposed via
srsly.msgpack
. However, we normally interact with it via the utility functions only.
Serialize an object to a msgpack byte string.
data = {"foo": "bar", "baz": 123}
msg = srsly.msgpack_dumps(data)
Argument | Type | Description |
---|---|---|
data |
- | The data to serialize. |
RETURNS | bytes | The serialized bytes. |
Deserialize msgpack bytes to a Python object.
msg = b"\x82\xa3foo\xa3bar\xa3baz{"
data = srsly.msgpack_loads(msg)
Argument | Type | Description |
---|---|---|
data |
bytes | The data to deserialize. |
use_list |
bool | Don't use tuples instead of lists. Can make deserialization slower. Defaults to True . |
RETURNS | - | The deserialized Python object. |
Create a msgpack file and dump contents.
data = {"foo": "bar", "baz": 123}
srsly.write_msgpack("/path/to/file.msg", data)
Argument | Type | Description |
---|---|---|
path |
str / Path |
The file path. |
data |
- | The data to serialize. |
Load a msgpack file.
data = srsly.read_msgpack("/path/to/file.msg")
Argument | Type | Description |
---|---|---|
path |
str / Path |
The file path. |
use_list |
bool | Don't use tuples instead of lists. Can make deserialization slower. Defaults to True . |
RETURNS | - | The loaded and deserialized content. |
📦 The underlying module is exposed via
srsly.cloudpickle
. However, we normally interact with it via the utility functions only.
Serialize a Python object with pickle.
data = {"foo": "bar", "baz": 123}
pickled_data = srsly.pickle_dumps(data)
Argument | Type | Description |
---|---|---|
data |
- | The object to serialize. |
protocol |
int | Protocol to use. -1 for highest. Defaults to None . |
RETURNS | bytes | The serialized object. |
Deserialize bytes with pickle.
pickled_data = b"\x80\x04\x95\x19\x00\x00\x00\x00\x00\x00\x00}\x94(\x8c\x03foo\x94\x8c\x03bar\x94\x8c\x03baz\x94K{u."
data = srsly.pickle_loads(pickled_data)
Argument | Type | Description |
---|---|---|
data |
bytes | The data to deserialize. |
RETURNS | - | The deserialized Python object. |
📦 The underlying module is exposed via
srsly.ruamel_yaml
. However, we normally interact with it via the utility functions only.
Serialize an object to a YAML string. See the
ruamel.yaml
docs
for details on the indentation format.
data = {"foo": "bar", "baz": 123}
yaml_string = srsly.yaml_dumps(data)
Argument | Type | Description |
---|---|---|
data |
- | The JSON-serializable data to output. |
indent_mapping |
int | Mapping indentation. Defaults to 2 . |
indent_sequence |
int | Sequence indentation. Defaults to 4 . |
indent_offset |
int | Indentation offset. Defaults to 2 . |
sort_keys |
bool | Sort dictionary keys. Defaults to False . |
RETURNS | str | The serialized string. |
Deserialize unicode or a file object to a Python object.
data = 'foo: bar\nbaz: 123'
obj = srsly.yaml_loads(data)
Argument | Type | Description |
---|---|---|
data |
str / file | The data to deserialize. |
RETURNS | - | The deserialized Python object. |
Create a YAML file and dump contents or write to standard output.
data = {"foo": "bar", "baz": 123}
srsly.write_yaml("/path/to/file.yml", data)
Argument | Type | Description |
---|---|---|
path |
str / Path |
The file path or "-" to write to stdout. |
data |
- | The JSON-serializable data to output. |
indent_mapping |
int | Mapping indentation. Defaults to 2 . |
indent_sequence |
int | Sequence indentation. Defaults to 4 . |
indent_offset |
int | Indentation offset. Defaults to 2 . |
sort_keys |
bool | Sort dictionary keys. Defaults to False . |
Load YAML from a file or standard input.
data = srsly.read_yaml("/path/to/file.yml")
Argument | Type | Description |
---|---|---|
path |
str / Path |
The file path or "-" to read from stdin. |
RETURNS | dict / list | The loaded YAML content. |
Check if a Python object is YAML-serializable.
assert srsly.is_yaml_serializable({"hello": "world"}) is True
assert srsly.is_yaml_serializable(lambda x: x) is False
Argument | Type | Description |
---|---|---|
obj |
- | The object to check. |
RETURNS | bool | Whether the object is YAML-serializable. |