How it is possible to avoid a push in Github when the workflow tests fails?

I create the workflow to test my Python application before commit. The problem is that if the tests fail, the commit is pushed anyways. How I could add a condition to avoid the push if the test don't succeed?

Structure of the workflow file .yml here below.

`name: Python application on: push: branches: [ master ] pull_request: branches: [ master ]

jobs: build:

runs-on: ubuntu-latest

steps:
- uses: actions/checkout@v2
- name: Set up Python 3.8
  uses: actions/setup-python@v1
  with:
    python-version: 3.8
- name: Install dependencies
  run: |
    python -m pip install --upgrade pip
    pip install -r requirements.txt
- name: Lint with flake8
  run: |
    pip install flake8
    # stop the build if there are Python syntax errors or undefined names
    flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
    # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
    flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
- name: Test with pytest
  run: |
    pip install pytest
    pytest`

Test fail screenshot