Azure Logic app - Pytest is getting failed

Question

I wrote Integration test using pytest in my python Azure Function app project. It is an Azure function app project. It's working fine in my local but getting a No Module found error in Azure Pipeline.

My project structure is,

sampleApi
|
---- __init__.py
---- __run__.py

library
|
---- core.py
---- utils.py
---- azure-storage.py

tests
|
---- sources
     |
-------- __init__.py   # To store all mock data
---- test_one.py
---- test_two.py
---- test_three.py
azure-pipelines.yaml
requirements.txt

In the parent directory of Local, I am running pytest using the following command.

pytest --doctest-modules --junitxml=junit/test-results.xml tests

We are not using a Virtual environment on the Azure pipeline. We are directly using it on the agent. Please find the below Azure-pipeline.yaml script

In Azure pipeline(azure-pipelines.yaml),

name : Build Report Function
trigger:
  branches:
    include:
    - Pytest_Pipeline

pool:
  vmImage: 'ubuntu-18.04'
  
stages:
- stage: Build
  displayName: Build Project
  jobs:  
  - job: Build
    displayName: Build & Test
    steps:
    - task: UsePythonVersion@0
      displayName: 'Use Python 3.8'
      inputs:
        versionSpec: 3.8
    
    - script: |
        python -m pip install --upgrade pip
        pip install --target="$(System.DefaultWorkingDirectory)/.python_packages/lib/site-packages" -r requirements.txt
        pip install pytest pytest-azurepipelines
        # pip install -e .
      displayName: 'Install dependencies'

    - script: |
        python -m pytest tests/
      displayName: 'pytest'

I am getting the following errors,

##[error]7 test(s) failed, 0 test(s) collected.

==================================== ERRORS ====================================
_________________ ERROR collecting tests/test_one.py _________________
tests/test_one.py:3: in <module>
    import pandas as pd
E   ModuleNotFoundError: No module named 'pandas'
_________________ ERROR collecting tests/test_one.py _________________

But I already added pandas in requirements.txt and it's working fine in my function app.

requirements.txt,

azure-functions
pymongo
dnspython
Jinja2
pandas
numpy
azure-storage-blob
python-pptx
openpyxl
python-dotenv