AttributeError: module 'typing' has no attribute '_ClassVar'

[mihaipanait]

I'm getting this error when running a python azure function that uses typedjson package on Python 3.7 and 3.8.
Apparently the exception is caused by the dependency to dataclasses = "^0.6.0" in python >= 3.7.

See this issue:
#konradhalas/dacite#48
#google/flax#269

This is a proposed fix:
#konradhalas/dacite#49
#DataBiosphere/hca-metadata-api@8357cf0

Here is the entire stack trace:
Result: Failure Exception: AttributeError: module 'typing' has no attribute '_ClassVar' Stack: File "/azure-functions-host/workers/python/3.8/LINUX/X64/azure_functions_worker/dispatcher.py", line 262, in _handle__function_load_request func = loader.load_function( File "/azure-functions-host/workers/python/3.8/LINUX/X64/azure_functions_worker/utils/wrappers.py", line 32, in call return func(*args, **kwargs) File "/azure-functions-host/workers/python/3.8/LINUX/X64/azure_functions_worker/loader.py", line 76, in load_function mod = importlib.import_module(fullmodname) File "/usr/local/lib/python3.8/importlib/init.py", line 127, in import_module return _bootstrap._gcd_import(name[level:], package, level) File "", line 1014, in _gcd_import File "", line 991, in _find_and_load File "", line 975, in _find_and_load_unlocked File "", line 671, in _load_unlocked File "", line 783, in exec_module File "", line 219, in _call_with_frames_removed File "/home/site/wwwroot/TelraamScheduler/main.py", line 13, in from ..Common.Telraam.scrape_segment_message import ScrapeSegmentMessage File "/home/site/wwwroot/Common/Telraam/scrape_segment_message.py", line 5, in class ScrapeSegmentMessage(): File "/home/site/wwwroot/.python_packages/lib/site-packages/dataclasses.py", line 958, in dataclass return wrap(_cls) File "/home/site/wwwroot/.python_packages/lib/site-packages/dataclasses.py", line 950, in wrap return _process_class(cls, init, repr, eq, order, unsafe_hash, frozen) File "/home/site/wwwroot/.python_packages/lib/site-packages/dataclasses.py", line 800, in _process_class cls_fields = [_get_field(cls, name, type) File "/home/site/wwwroot/.python_packages/lib/site-packages/dataclasses.py", line 800, in cls_fields = [_get_field(cls, name, type) File "/home/site/wwwroot/.python_packages/lib/site-packages/dataclasses.py", line 659, in _get_field if (_is_classvar(a_type, typing) File "/home/site/wwwroot/.python_packages/lib/site-packages/dataclasses.py", line 550, in _is_classvar return type(a_type) is typing._ClassVar

Here are the dependecies log installed on azure:
2020-07-29T12:31:36.1317512Z ##[section]Starting: Install dependencies
2020-07-29T12:31:36.1324393Z ==============================================================================
2020-07-29T12:31:36.1324711Z Task : Bash
2020-07-29T12:31:36.1324987Z Description : Run a Bash script on macOS, Linux, or Windows
2020-07-29T12:31:36.1325234Z Version : 3.171.1
2020-07-29T12:31:36.1325456Z Author : Microsoft Corporation
2020-07-29T12:31:36.1325787Z Help : https://docs.microsoft.com/azure/devops/pipelines/tasks/utility/bash
2020-07-29T12:31:36.1326148Z ==============================================================================
2020-07-29T12:31:36.2840459Z Generating script.
2020-07-29T12:31:36.2872017Z ========================== Starting Command Output ===========================
2020-07-29T12:31:36.2889718Z [command]/bin/bash --noprofile --norc /home/vsts/work/_temp/d2b8fe8f-7b7e-4b41-8ec8-a516d419af47.sh
2020-07-29T12:31:42.4588411Z Looking in indexes:
2020-07-29T12:31:42.4590870Z Requirement already satisfied: setuptools in ./worker_venv/lib/python3.8/site-packages (41.2.0)
2020-07-29T12:31:42.8960266Z WARNING: You are using pip version 19.2.3, however version 20.2 is available.
2020-07-29T12:31:42.8962114Z You should consider upgrading via the 'pip install --upgrade pip' command.
2020-07-29T12:31:43.3845340Z Collecting azure-functions (from -r azure_functions_scrapers/requirements.txt (line 1))
2020-07-29T12:31:43.9762247Z Downloading https://files.pythonhosted.org/packages/da/ab/4380cf9683fba6412022b2636797445e60ba5d030f1373769a868acedfd1/azure_functions-1.3.0-py3-none-any.whl (120kB)
2020-07-29T12:31:44.0303337Z Collecting requests (from -r azure_functions_scrapers/requirements.txt (line 2))
2020-07-29T12:31:44.3030806Z Downloading https://files.pythonhosted.org/packages/45/1e/0c169c6a5381e241ba7404532c16a21d86ab872c9bed8bdcd4c423954103/requests-2.24.0-py2.py3-none-any.whl (61kB)
2020-07-29T12:31:44.3332093Z Collecting azure-storage-blob (from -r azure_functions_scrapers/requirements.txt (line 3))
2020-07-29T12:31:44.5925547Z Downloading https://files.pythonhosted.org/packages/6d/3d/31614573e8a197db12d8ab47a7fd813f15bd4a4b5c64e85d23b865de5b9b/azure_storage_blob-12.3.2-py2.py3-none-any.whl (280kB)
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2020-07-29T12:31:44.8010268Z Downloading https://files.pythonhosted.org/packages/8b/00/efb68e2dda82139d732090fc3b7ff47fe6f34724ea7ba31e518a854b15c1/azure_core-1.7.0-py2.py3-none-any.whl (121kB)
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2020-07-29T12:31:45.1700689Z Collecting geographiclib (from -r azure_functions_scrapers/requirements.txt (line 6))
2020-07-29T12:31:45.3825928Z Downloading https://files.pythonhosted.org/packages/8b/62/26ec95a98ba64299163199e95ad1b0e34ad3f4e176e221c40245f211e425/geographiclib-1.50-py3-none-any.whl
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2020-07-29T12:31:45.8378246Z Downloading https://files.pythonhosted.org/packages/5d/9f/f4c2a0f6f03d3ba95043c616e477926776ed3de7963a80edede7599630de/pandas-1.1.0-cp38-cp38-manylinux1_x86_64.whl (10.3MB)
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2020-07-29T12:31:47.0524402Z Collecting capacity-ai-datadefinitions==0.0.36 (from -r azure_functions_scrapers/requirements.txt (line 9))
2020-07-29T12:31:47.6751131Z Collecting openlocationcode<2,>=1 (from -r azure_functions_scrapers/requirements.txt (line 10))
2020-07-29T12:31:47.8898231Z Downloading https://files.pythonhosted.org/packages/50/e8/9fc58ee30f4f7b1befe190005c3d0d50b472df4bb968dcae1db7fbbf0e2a/openlocationcode-1.0.1.tar.gz
2020-07-29T12:31:48.7315786Z Collecting azure-storage-queue==2.1.0 (from -r azure_functions_scrapers/requirements.txt (line 11))
2020-07-29T12:31:48.8745190Z Downloading https://files.pythonhosted.org/packages/69/08/a0dcde53f9203fa83111e28fc368404c818a8c54c077ae66559b237c9dd4/azure_storage_queue-2.1.0-py2.py3-none-any.whl
2020-07-29T12:31:48.8903240Z Collecting typedjson (from -r azure_functions_scrapers/requirements.txt (line 12))
2020-07-29T12:31:49.1041854Z Downloading https://files.pythonhosted.org/packages/c3/4c/30b63a61089ca91727f5c0be70488954988a20048c89f2a84455f4e798b9/typedjson-0.7.5-py3-none-any.whl
2020-07-29T12:31:49.1163806Z Collecting python-dateutil==2.8.1 (from -r azure_functions_scrapers/requirements.txt (line 13))
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2020-07-29T12:31:49.4698927Z Downloading https://files.pythonhosted.org/packages/17/5d/1b9d6d3c7995fff473f35861d674e0113a5f0bd5a72fe0199c3f254665c7/freezegun-0.3.15-py2.py3-none-any.whl
2020-07-29T12:31:49.4832988Z Collecting certifi>=2017.4.17 (from requests->-r azure_functions_scrapers/requirements.txt (line 2))
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2020-07-29T12:31:50.0514876Z Collecting urllib3!=1.25.0,!=1.25.1,<1.26,>=1.21.1 (from requests->-r azure_functions_scrapers/requirements.txt (line 2))
2020-07-29T12:31:50.2650674Z Downloading https://files.pythonhosted.org/packages/9f/f0/a391d1463ebb1b233795cabfc0ef38d3db4442339de68f847026199e69d7/urllib3-1.25.10-py2.py3-none-any.whl (127kB)
2020-07-29T12:31:50.2983817Z Collecting msrest>=0.6.10 (from azure-storage-blob->-r azure_functions_scrapers/requirements.txt (line 3))
2020-07-29T12:31:50.4805409Z Downloading https://files.pythonhosted.org/packages/d9/ed/8e1b75721ad983c1672cd968ad3ae374d2e94767edff6f0b72a15dfde933/msrest-0.6.18-py2.py3-none-any.whl (84kB)
2020-07-29T12:31:50.5134796Z Collecting cryptography>=2.1.4 (from azure-storage-blob->-r azure_functions_scrapers/requirements.txt (line 3))
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2020-07-29T12:31:51.2471110Z Collecting six>=1.6 (from azure-core->-r azure_functions_scrapers/requirements.txt (line 4))
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2020-07-29T12:31:51.9329291Z Collecting cachecontrol (from mapbox->-r azure_functions_scrapers/requirements.txt (line 5))
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2020-07-29T12:31:52.1024416Z Collecting boto3>=1.4 (from mapbox->-r azure_functions_scrapers/requirements.txt (line 5))
2020-07-29T12:31:52.5889190Z Downloading https://files.pythonhosted.org/packages/d4/e4/3f163596bc07259b4fca48ef5668d5ad5be330c2b36c7fdadb9e0401745e/boto3-1.14.30-py2.py3-none-any.whl (129kB)
2020-07-29T12:31:52.6164569Z Collecting numpy>=1.15.4 (from pandas->-r azure_functions_scrapers/requirements.txt (line 7))
2020-07-29T12:31:53.2575017Z Downloading https://files.pythonhosted.org/packages/c7/44/e17846ef3601dcb6f118ea447439650e0c35cb4fe60274fbe24214156df2/numpy-1.19.1-cp38-cp38-manylinux2010_x86_64.whl (14.5MB)
2020-07-29T12:31:53.9259514Z Collecting pytz>=2017.2 (from pandas->-r azure_functions_scrapers/requirements.txt (line 7))
2020-07-29T12:31:54.2661653Z Downloading https://files.pythonhosted.org/packages/4f/a4/879454d49688e2fad93e59d7d4efda580b783c745fd2ec2a3adf87b0808d/pytz-2020.1-py2.py3-none-any.whl (510kB)
2020-07-29T12:31:54.3927347Z Requirement already satisfied: setuptools in ./worker_venv/lib/python3.8/site-packages (from protobuf<4,>=3->-r azure_functions_scrapers/requirements.txt (line 8)) (41.2.0)
2020-07-29T12:31:54.3994949Z Collecting azure-common>=1.1.5 (from azure-storage-queue==2.1.0->-r azure_functions_scrapers/requirements.txt (line 11))
2020-07-29T12:31:54.5934730Z Downloading https://files.pythonhosted.org/packages/e5/4d/d000fc3c5af601d00d55750b71da5c231fcb128f42ac95b208ed1091c2c1/azure_common-1.1.25-py2.py3-none-any.whl
2020-07-29T12:31:54.6061271Z Collecting azure-storage-common~=2.1 (from azure-storage-queue==2.1.0->-r azure_functions_scrapers/requirements.txt (line 11))
2020-07-29T12:31:54.7651404Z Downloading https://files.pythonhosted.org/packages/6b/a0/6794b318ce0118d1a4053bdf0149a60807407db9b710354f2b203c2f5975/azure_storage_common-2.1.0-py2.py3-none-any.whl (47kB)
2020-07-29T12:31:54.7851544Z Collecting dataclasses<0.7.0,>=0.6.0 (from typedjson->-r azure_functions_scrapers/requirements.txt (line 12))
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2020-07-29T12:31:54.9580000Z Collecting typing-extensions<4.0,>=3.7 (from typedjson->-r azure_functions_scrapers/requirements.txt (line 12))
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2020-07-29T12:31:55.1671193Z Collecting requests-oauthlib>=0.5.0 (from msrest>=0.6.10->azure-storage-blob->-r azure_functions_scrapers/requirements.txt (line 3))
2020-07-29T12:31:55.3107025Z Downloading https://files.pythonhosted.org/packages/a3/12/b92740d845ab62ea4edf04d2f4164d82532b5a0b03836d4d4e71c6f3d379/requests_oauthlib-1.3.0-py2.py3-none-any.whl
2020-07-29T12:31:55.3261599Z Collecting isodate>=0.6.0 (from msrest>=0.6.10->azure-storage-blob->-r azure_functions_scrapers/requirements.txt (line 3))
2020-07-29T12:31:55.4673569Z Downloading https://files.pythonhosted.org/packages/9b/9f/b36f7774ff5ea8e428fdcfc4bb332c39ee5b9362ddd3d40d9516a55221b2/isodate-0.6.0-py2.py3-none-any.whl (45kB)
2020-07-29T12:31:55.4817923Z Collecting cffi!=1.11.3,>=1.8 (from cryptography>=2.1.4->azure-storage-blob->-r azure_functions_scrapers/requirements.txt (line 3))
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2020-07-29T12:31:55.8919218Z Collecting msgpack>=0.5.2 (from cachecontrol->mapbox->-r azure_functions_scrapers/requirements.txt (line 5))
2020-07-29T12:31:56.0583150Z Downloading https://files.pythonhosted.org/packages/ba/cf/85e60b003ee5e8ba83c36872320f2dc4eca791350910c8dffeab0bd1672c/msgpack-1.0.0-cp38-cp38-manylinux1_x86_64.whl (303kB)
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2020-07-29T12:31:57.2383361Z Collecting s3transfer<0.4.0,>=0.3.0 (from boto3>=1.4->mapbox->-r azure_functions_scrapers/requirements.txt (line 5))
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2020-07-29T12:31:57.4302314Z Collecting jmespath<1.0.0,>=0.7.1 (from boto3>=1.4->mapbox->-r azure_functions_scrapers/requirements.txt (line 5))
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2020-07-29T12:31:57.9697762Z Collecting docutils<0.16,>=0.10 (from botocore<1.18.0,>=1.17.30->boto3>=1.4->mapbox->-r azure_functions_scrapers/requirements.txt (line 5))
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2020-07-29T12:31:58.3191857Z Installing collected packages: azure-functions, certifi, idna, chardet, urllib3, requests, oauthlib, requests-oauthlib, six, isodate, msrest, pycparser, cffi, cryptography, azure-core, azure-storage-blob, iso3166, uritemplate, polyline, python-dateutil, msgpack, cachecontrol, docutils, jmespath, botocore, s3transfer, boto3, mapbox, geographiclib, numpy, pytz, pandas, protobuf, capacity-ai-datadefinitions, openlocationcode, azure-common, azure-storage-common, azure-storage-queue, dataclasses, typing-extensions, typedjson, freezegun
2020-07-29T12:32:07.2638344Z Running setup.py install for openlocationcode: started
2020-07-29T12:32:07.5971977Z Running setup.py install for openlocationcode: finished with status 'done'
2020-07-29T12:32:07.7348544Z Successfully installed azure-common-1.1.25 azure-core-1.7.0 azure-functions-1.3.0 azure-storage-blob-12.3.2 azure-storage-common-2.1.0 azure-storage-queue-2.1.0 boto3-1.14.30 botocore-1.17.30 cachecontrol-0.12.6 capacity-ai-datadefinitions-0.0.36 certifi-2020.6.20 cffi-1.14.1 chardet-3.0.4 cryptography-3.0 dataclasses-0.6 docutils-0.15.2 freezegun-0.3.15 geographiclib-1.50 idna-2.10 iso3166-1.0.1 isodate-0.6.0 jmespath-0.10.0 mapbox-0.18.0 msgpack-1.0.0 msrest-0.6.18 numpy-1.19.1 oauthlib-3.1.0 openlocationcode-1.0.1 pandas-1.1.0 polyline-1.4.0 protobuf-3.12.2 pycparser-2.20 python-dateutil-2.8.1 pytz-2020.1 requests-2.24.0 requests-oauthlib-1.3.0 s3transfer-0.3.3 six-1.15.0 typedjson-0.7.5 typing-extensions-3.7.4.2 uritemplate-3.0.1 urllib3-1.25.10
2020-07-29T12:32:07.9797064Z WARNING: You are using pip version 19.2.3, however version 20.2 is available.
2020-07-29T12:32:07.9798382Z You should consider upgrading via the 'pip install --upgrade pip' command.
2020-07-29T12:32:08.0404274Z
2020-07-29T12:32:08.0468437Z ##[section]Finishing: Install dependencies

[mitsuse]

@mihaipanait Thanks for reporting! I fixed this issue. Please try the version 0.8.0. You can also check that dataclasses is not installed any more with Python 3.7.x on Travis CI:

• 3.6.x: https://travis-ci.org/github/mitsuse/typedjson-python/jobs/713225725
• 3.7.x: https://travis-ci.org/github/mitsuse/typedjson-python/jobs/713225726

[mihaipanait]

It works! Thanks for the quick fix!