AttributeError: module 'hl7apy.v2_5' has no attribute 'get'

I am seeing the following error/stacktrace when using hl7apy in a REST API written in Python3.7, running on a Flask/Gunicorn web server with 2 worker processes and multiple threads per worker.

Traceback (most recent call last):
  File "venv/lib/python3.7/site-packages/flask/app.py", line 1813, in full_dispatch_request
    rv = self.dispatch_request()
  File "venv/lib/python3.7/site-packages/flask/app.py", line 1799, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/middleware.py", line 189, in wrapped_f
    return f(*args, **kwargs)
  File "upload_api.py", line 60, in receive_message
    parsed_message = parse(appt_msg_hl7)
  File "hl7/parser.py", line 50, in parse
    return parse_message(message.replace('\n', '\r'), find_groups=False)
  File "venv/lib/python3.7/site-packages/hl7apy/parser.py", line 82, in parse_message
    validation_level=validation_level, encoding_chars=encoding_chars)
  File "venv/lib/python3.7/site-packages/hl7apy/core.py", line 1914, in __init__
    validation_level)
  File "venv/lib/python3.7/site-packages/hl7apy/core.py", line 1784, in __init__
    super(Group, self).__init__(name, parent, reference, version, validation_level, traversal_parent)
  File "venv/lib/python3.7/site-packages/hl7apy/core.py", line 638, in __init__
    self._find_structure(reference)
  File "venv/lib/python3.7/site-packages/hl7apy/core.py", line 813, in _find_structure
    structure = ElementFinder.get_structure(self, reference)
  File "venv/lib/python3.7/site-packages/hl7apy/core.py", line 546, in get_structure
    reference = load_reference(element.name, element.classname, element.version)
  File "venv/lib/python3.7/site-packages/hl7apy/__init__.py", line 280, in load_reference
    ref = lib.get(name, element_type)
AttributeError: module 'hl7apy.v2_5' has no attribute 'get'

Some other useful information:

• I am able to successfully parse the offending messages on my local setup, so this only seems to happen in my multithreaded production environment.
• This error also occurs with hl7apy.v2_4, so it is not peculiar to hl7apy.v2.5.
• This problem is intermittent i.e. messages are parsed successfully 90% of the time, but there are a few so-far-unpredictable instances where this error occurs at runtime.

Could it be that certain aspects of the hl7apy implementation are not thread-safe? Is hl7apy thread-safe? Or is this caused by something else entirely that I may be overlooking? Please help!

[shamim40]

I appreciate ur quick response. What is the timeline for the release?

[svituz]

Hi @shamim40, the multithreading issue is fixed in the develop branch, but we have not released it yet. If you want you can use it by cloning this repo, moving to the develop branch and installing the library from it.