About
This library provides encoding and decoding for the Concise Binary Object Representation (CBOR) (RFC 7049) serialization format. Read the docs to learn more.
It is implemented in pure python with an optional C backend.
On PyPy, cbor2 runs with almost identical performance to the C backend.
Features
- Simple api like
json
orpickle
modules. - Support many CBOR tags with stdlib objects.
- Generic tag decoding.
- Shared value references including cyclic references.
- Optional C module backend tested on big- and little-endian architectures.
- Extensible tagged value handling using
tag_hook
andobject_hook
on decode anddefault
on encode. - Command-line diagnostic tool, converting CBOR file or stream to JSON
python -m cbor2.tool
(This is a lossy conversion, for diagnostics only) - Thorough test suite.
Installation
pip install cbor2
Requirements
- Python >= 3.6 (or PyPy3 3.6+)
- C-extension: Any C compiler that can build Python extensions. Any modern libc with the exception of Glibc<2.9
Building the C-Extension
To force building of the optional C-extension, set OS env CBOR2_BUILD_C_EXTENSION=1
.
To disable building of the optional C-extension, set OS env CBOR2_BUILD_C_EXTENSION=0
.
If this environment variable is unset, setup.py will default to auto detecting a compatible C library and
attempt to compile the extension.
Usage
Command-line Usage
python -m cbor2.tool
converts CBOR data in raw binary or base64 encoding into
a representation that allows printing as JSON. This is a lossy transformation as
each datatype is converted into something that can be represented as a JSON value.
Usage:
# Pass hexadecimal through xxd. $ echo a16568656c6c6f65776f726c64 | xxd -r -ps | python -m cbor2.tool --pretty { "hello": "world" } # Decode Base64 directly $ echo ggEC | python -m cbor2.tool --decode [1, 2] # Read from a file encoded in Base64 $ python -m cbor2.tool -d tests/examples.cbor.b64 {...}
It can be used in a pipeline with json processing tools like jq to allow syntax coloring, field extraction and more.
CBOR data items concatenated into a sequence can be decoded also:
$ echo ggECggMEggUG | python -m cbor2.tool -d --sequence [1, 2] [3, 4] [5, 6]
Multiple files can also be sent to a single output file:
$ python -m cbor2.tool -o all_files.json file1.cbor file2.cbor ... fileN.cbor
Security
This library has not been tested against malicious input. In theory it should be
as safe as JSON, since unlike pickle
the decoder does not execute any code.