Why Every Data Analyst Should Learn Django in 2026

#!/usr/bin/env bash
set -euo pipefail
python -m venv .venv && source .venv/bin/activate
pip install django pandas
django-admin startproject reportsite .
python manage.py startapp reports
# add 'reports' to INSTALLED_APPS in reportsite/settings.py
python manage.py migrate
python manage.py createsuperuser
python manage.py runserver

# reports/cleaning.py: plain pandas, testable outside Django
import pandas as pd

REQUIRED = {"order_id", "order_date", "region", "amount"}

def clean_sales(file) -> tuple[pd.DataFrame, list[str]]:
    df = pd.read_csv(file)
    df.columns = [c.strip().lower().replace(" ", "_") for c in df.columns]
    missing = REQUIRED - set(df.columns)
    if missing:
        return pd.DataFrame(), [f"missing columns: {sorted(missing)}"]
    df["order_date"] = pd.to_datetime(df["order_date"], errors="coerce", dayfirst=True)
    df["amount"] = pd.to_numeric(df["amount"], errors="coerce")
    df["region"] = df["region"].str.strip().str.title()
    problems = []
    bad = df["order_date"].isna() | df["amount"].isna()
    if bad.any():
        problems.append(f"{int(bad.sum())} rows with bad dates or amounts removed")
    df = df[~bad].drop_duplicates("order_id")
    return df, problems

# reports/models.py
from django.db import models

class Sale(models.Model):
    order_id = models.CharField(max_length=50, unique=True)
    order_date = models.DateField()
    region = models.CharField(max_length=50)
    amount = models.DecimalField(max_digits=12, decimal_places=2)

# reports/forms.py
from django import forms

class UploadForm(forms.Form):
    file = forms.FileField(help_text="CSV with order_id, order_date, region, amount")

from django.contrib.auth.decorators import login_required
from django.shortcuts import render

from .cleaning import clean_sales
from .forms import UploadForm
from .models import Sale

@login_required
def upload(request):
    form = UploadForm(request.POST or None, request.FILES or None)
    context = {"form": form}
    if request.method == "POST" and form.is_valid():
        df, problems = clean_sales(request.FILES["file"])
        if not df.empty:
            Sale.objects.bulk_create(
                [Sale(order_id=r.order_id, order_date=r.order_date.date(),
                      region=r.region, amount=r.amount) for r in df.itertuples()],
                ignore_conflicts=True,   # skip order_ids already saved
            )
        context.update(saved=len(df), problems=problems)
    return render(request, "reports/upload.html", context)

import pandas as pd
from django.contrib.auth.decorators import login_required
from django.shortcuts import render

from .models import Sale

@login_required
def region_report(request):
    qs = Sale.objects.all()
    region = request.GET.get("region")
    if region:
        qs = qs.filter(region=region)
    df = pd.DataFrame(qs.values("order_date", "region", "amount"))
    table = []
    if not df.empty:
        df["amount"] = df["amount"].astype(float)
        df["month"] = pd.to_datetime(df["order_date"]).dt.to_period("M").astype(str)
        summary = df.groupby(["month", "region"], as_index=False)["amount"].sum()
        table = summary.to_dict("records")
    return render(request, "reports/region.html", {"rows": table, "region": region})

import csv

from django.contrib.auth.decorators import login_required
from django.http import HttpResponse

from .models import Sale

@login_required
def download_csv(request):
    response = HttpResponse(content_type="text/csv")
    response["Content-Disposition"] = 'attachment; filename="sales.csv"'
    writer = csv.writer(response)
    writer.writerow(["order_id", "order_date", "region", "amount"])
    qs = Sale.objects.all()
    if request.GET.get("region"):
        qs = qs.filter(region=request.GET["region"])
    for s in qs.order_by("order_date"):
        writer.writerow([s.order_id, s.order_date, s.region, s.amount])
    return response

Project: Sales upload and report app

- Upload page: CSV validated and cleaned with pandas
- Clear error messages for bad files
- Sale model; duplicates skipped by order_id
- Region report page with filters and a summary table
- CSV download of filtered data
- Admin for monthly targets
- Login required for all pages
- Tests for the cleaning function
- README with screenshots

Week 1  Django tutorial: views, URLs, templates, admin
Week 2  Upload form and pandas cleaning function
Week 3  Report view, filters and CSV download
Week 4  Login, admin for targets, tests, README

# tests/test_cleaning.py   Run: pytest (cleaning.py is plain pandas)
import io
from reports.cleaning import clean_sales

def test_bad_rows_removed():
    csv = io.StringIO(
        "Order ID,Order Date,Region,Amount\n"
        "A1,05/01/2026, north ,100\n"
        "A2,not-a-date,South,50\n"
    )
    df, problems = clean_sales(csv)
    assert list(df["order_id"]) == ["A1"]
    assert df["region"].iloc[0] == "North"
    assert problems