Source: https://daphnislabs.com/services/python-development

# Python Development

Python services, APIs and automation for business products, with explicit data contracts, background work and operational handover.

[Discuss your project](https://daphnislabs.com/contact?service=python-development) [Try the example](https://daphnislabs.com/services/python-development#worked-example)

**catalogue\_import.py**

`for row in catalogue:   result = validate(row)   if result.valid:   queue.upsert(row)   else:   report.add(result.errors)`

Valid rows Correction report

## Tools & technologies

-   Python
-   Django or FastAPI
-   PostgreSQL
-   Task queue

## Import a supplier catalogue

Capability Example

A supplier uploads a CSV with valid rows, duplicates and missing prices.

### Validate

### Process

### Report

Illustrative data. Nothing is sent to an external system.

Example workspace 1 / 3

### CSV validation

```
row 1: valid
row 2: duplicate SKU
row 3: price missing
```

Check the file schema and collect row-level errors.

### Import job

```
valid row processed
invalid rows isolated
job_id: import-17
```

Upsert valid rows in bounded batches with a resumable job ID.

### Import report

```
accepted: row 1
corrections: rows 2 and 3
retry uses the same import ID
```

Return accepted, rejected and unchanged record counts.

An import result with actionable row errors and a repeatable retry path.

Follow the record through the next step

## Services and jobs with explicit data contracts.

### Backend services

Implement application rules and integrate data from existing systems.

### Processing jobs

Validate files, transform records and schedule repeatable operations.

### Existing Python systems

Maintain frameworks, improve test coverage and untangle slow or fragile jobs.

## Code your team can run and change.

-   **Python service source**
-   **API and data schemas**

-   **Worker and failure-path tests**
-   **Deployment and operations guide**

## Separate the request from the long-running work.

### Workload shape

Separate interactive API latency from long-running processing needs.

### Data ownership

Define validation and conflict rules before allowing imported data to overwrite records.

## Questions before we start.

### Do we need Django or FastAPI?

Choose from the product's needs: administration, authentication, API contracts and existing code matter more than framework preference.

### Can Python connect to an existing frontend?

Yes. It can expose an API for React, Vue, Angular or mobile clients without replacing those interfaces.

[Full Stack Development](https://daphnislabs.com/services/full-stack-development) [Machine Learning Development](https://daphnislabs.com/services/machine-learning) [Data Engineering](https://daphnislabs.com/services/data-engineering)

## Bring your starting point.

Share the data flow, existing integrations and examples of successful and failed inputs.

[Discuss your project](https://daphnislabs.com/contact?service=python-development) [Explore related services](https://daphnislabs.com/services/full-stack-development)