Copyright 2012-2016 Johns Hopkins University HLTCOE. All rights reserved. This software is released under the 2-clause BSD license. See LICENSE.md in the project root directory.

Python modules and scripts for working with Concrete, an HLT data specification defined using Thrift.

This repository contains the Python classes generated by the Thrift compiler, but not the .thrift definition files that were used to generate these classes. The .thrift definition files can be found in the Concrete GitHub repository: https://github.com/hltcoe/concrete

The accel branch of Concrete-Python supports the accelerated thrift protocols. For many workloads these are 10 to 30 times faster than the pure Python protocols. To take advantage of them, check out the accel branch from the Concrete-Python Git repository and follow the README there to install.

Concrete-Python requires Python 2.7 and the Thrift Python library, among other Python libraries. These are installed automatically by setup.py or pip. The Thrift compiler is not required.

Note on Windows compatibility: The 'thrift' Python package (and thus the Concrete Python package) does not seem to work with the Python Windows binaries from Python.org (32 and 64-bit versions) on 64-bit Windows. The 'thrift' package does work using the version of Python that comes with 64-bit Cygwin on 64-bit Windows.

You can install Concrete using the pip package manager:

pip install concrete

or by cloning the repository and running setup.py:

git clone https://github.com/hltcoe/concrete-python.git
cd concrete-python
python setup.py test
python setup.py install

The Concrete Python package comes with three scripts:

• concrete_inspect.py reads in a Concrete Communication and prints out human-readable information about the Communication's contents (such as tokens, POS and NER tags, Entities, Situations, etc) to stdout.

• concrete2json.py reads in a Concrete Communication and prints a JSON version of the Communication to stdout. The JSON is "pretty printed" with indentation and whitespace, which makes the JSON easier to read and to use for diffs.

• validate_communication.py reads in a Concrete Communication file and prints out information about any invalid fields. This script is a command-line wrapper around the functionality in the concrete.validate library.

Use the --help flag for details about the scripts' command line arguments.

Compiled Python classes end up in the concrete namespace. You can use them by importing them as follows:

from concrete import Communication

foo = Communication()
foo.text = 'hello world'
...

The Python version of the Thrift Libraries does not perform any validation of Thrift objects. You should use the validate_communication() function after reading and before writing a Concrete Communication:

from concrete.util import read_communication_from_file
from concrete.validate import validate_communication

comm = read_communication_from_file('tests/testdata/serif_dog-bites-man.concrete')

# Returns True|False, logs details using Python stdlib 'logging' module
validate_communication(comm)

Thrift fields have three levels of requiredness:

• explicitly labeled as required
• explicitly labeled as optional
• no requiredness label given ("default required")

The Java version of the Thrift libraries will raise an exception if a required field is missing on deserialization or serialization, and will raise an exception if a "default required" field is missing on serialization. The Python version of the Thrift Libraries (as of Thrift 0.9.1) does not perform any validation of Thrift objects on serialization or deserialization. The Python Thrift libraries do provide a validate() function, but this function only checks for explicitly required fields, and not "default required" fields. The Thrift validate() function also only performs shallow validation - nested data structures are not checked for required fields.

The validate_communication() function recursively checks a Communication object for required fields, plus additional checks for UUID mismatches.

To rebuild the concrete-python sources from the concrete thrift definitions, use build.bash. This script takes the path to the thrift subdirectory of the concrete repository as an optional argument, generates the Python sources from the thrift definitions in that subdirectory, and patches to the generated code as necessary.