uninstall packages in azure function - python-3.x

Question

My azure function app(python) is throwing an exception: module typing has no attribute '_classVar'. A fix for this would be to uninstall the dataclasses package. How do I uninstall this package on a python azure function using pip?
If I run pip uninstall dataclasses, will this reflect on deployment?

Answer 1

If you are using python version 3.7 or greater you need to uninstall the dataclass library using the same pip uninstall dataclasses.
As The dataclasses package is a backport of the Python 3.7 dataclass functionality.
Or, if still you want to exist dataclasses you can downgrade your python version to 3.6.
For more information please refer the below links:
Blog|AttributeError: module ‘typing’ has no attribute ‘_ClassVar’ with Tune
Similar GitHub Issue

Answer 2

I was also having a lot of trouble trying to deploy azure functions from an Azure Devops pipeline with a Python 3.7 environment, so I decided to place this here as it might help someone else with the same problem.
You need to prepare the following yaml file with your respective variables.
trigger:
- {{ branch }}
variables:
# Azure Resource Manager connection created during pipeline creation
azureSubscription: '{{ azureRmConnection.Id }}'
# Function app name
functionAppName: '{{ functionAppName }}'
# Agent VM image name
vmImageName: 'ubuntu-latest'
# Working Directory
workingDirectory: '{{ workingDirectory }}'
stages:
- stage: Build
displayName: Build stage
jobs:
- job: Build
displayName: Build
pool:
vmImage: $(vmImageName)
steps:
- bash: |
if [ -f extensions.csproj ]
then
dotnet build extensions.csproj --runtime ubuntu.16.04-x64 --output ./bin
fi
workingDirectory: $(workingDirectory)
displayName: 'Build extensions'
- task: UsePythonVersion#0
displayName: 'Use Python 3.6'
inputs:
versionSpec: 3.6 # Functions V2 supports Python 3.6 as of today
- bash: |
pip install --target="./.python_packages/lib/site-packages" -r ./requirements.txt
rm -rf ./.python_packages/lib/site-packages/dataclasses-0.6*
rm ./.python_packages/lib/site-packages/dataclasses.py
workingDirectory: $(workingDirectory)
displayName: 'Install application dependencies'
- task: ArchiveFiles#2
displayName: 'Archive files'
inputs:
rootFolderOrFile: '$(workingDirectory)'
includeRootFolder: false
archiveType: zip
archiveFile: $(Build.ArtifactStagingDirectory)/$(Build.BuildId).zip
replaceExistingArchive: true
- publish: $(Build.ArtifactStagingDirectory)/$(Build.BuildId).zip
artifact: drop
- stage: Deploy
displayName: Deploy stage
dependsOn: Build
condition: succeeded()
jobs:
- deployment: Deploy
displayName: Deploy
environment: 'development'
pool:
vmImage: $(vmImageName)
strategy:
runOnce:
deploy:
steps:
- task: AzureFunctionApp#1
displayName: 'Azure functions app deploy'
inputs:
azureSubscription: '$(azureSubscription)'
appType: functionAppLinux
appName: $(functionAppName)
package: '$(Pipeline.Workspace)/drop/$(Build.BuildId).zip'
These are the key lines after installing the requirements.txt. These will remove the package from the site-packages folder.
rm -rf ./.python_packages/lib/site-packages/dataclasses-0.6*
rm ./.python_packages/lib/site-packages/dataclasses.py
pip uninstall dataclasses will not work because you are not in the right folder.
Hope this helps!