challenge_backend

challenge_backend is a Python application which implements the assignment as defined in "Challenge_Backend_South_African_Numbers_.pdf"

Minimum requirements

python 3.8.1

fastapi==0.61.0
mock~=4.0.2
numpy==1.19.1
pandas==1.1.0
pydantic==1.6.1
python-dateutil==2.8.1
pytz==2020.1
six==1.15.0
starlette==0.13.6

Usage

Open terminal and install the necessary packages by running:

pip install -r requirements.txt

Then start the application by running:

uvicorn main:app

For running the tests, do:

pytest

Go to http://127.0.0.1:8000/docs to consult the interactive documentation.

Features

The application allows a user to check if a number is a valid South African mobile phone number, based on the following assumptions:

• a valid number must contain 11 digits; and
• a valid number must begin with 27.

If a number contains 10 or 9 digits, the application will try to suggest a correction by adding the prefix 27, e.g. 7234567890 --> 27345678901.

By sending a GET request to the endpoint '/', a html form shall be provided to the user. By sending the form with a number, the application will confirm if the number is corrected, or not. If not correct, the user shall be notified on the reasons for which the number is not correct, and the possible correction.

The user may upload a csv file with a POST request to the endpoint '/upload-file' (parameter: file). The response shall be a json, dividing the numbers in three categories: 'accepted', 'corrected', 'rejected'.

Example of accepted number:

{
    "id_": 103426000,
    "number": "27718159078",
    "status": "accepted",
    "suggested_correction": null,
    "annotation": null
},

Example of corrected number:

{
    "id_": 103300640,
    "number": "730276061",
    "status": "corrected",
    "suggested_correction": "27730276061",
    "annotation": "Correction: missing 27 prefix"
},

Example of rejected number:

{
    "id_": 103343262,
    "number": "6478342944",
    "status": "rejected",
    "suggested_correction": null,
    "annotation": "Rejection: the number does not contain 11 digits; the number prefix is not 27."
},

Implementation notes

For the implementation, the following assumption has been made:

• the client uploaded file is indeed a csv file, without missing data; and
• the application will reject a csv file without columns name 'id' and 'sms_phone' number.

The parsing of the csv file is done with pandas library. For the purpose of this application the standard csv module might have been sufficient; however it is somehow awkward to work with while dealing iwth uploaded files.

As required by the assignment, a temporary file is created by main.py during the execution of the application.