Automation with Python: files, Excel reports, web APIs and scheduled tasks

from pathlib import Path

# Set up some sample files (in real life these would already exist)
folder = Path("photos")
folder.mkdir(exist_ok=True)
for name in ["IMG_001.JPG", "IMG_002.JPG", "IMG_003.jpg", "notes.txt"]:
    (folder / name).write_text("x")

# Rename all photos to a clean pattern, with a DRY RUN first
def rename_photos(folder, prefix, dry_run=True):
    photos = sorted(p for p in folder.iterdir() if p.suffix.lower() == ".jpg")
    for i, p in enumerate(photos, start=1):
        new = folder / f"{prefix}-{i:03d}{p.suffix.lower()}"
        print(("Would rename" if dry_run else "Renaming"), p.name, "->", new.name)
        if not dry_run:
            p.rename(new)

rename_photos(folder, "wedding-kamau")             # dry run: just shows what will happen
rename_photos(folder, "wedding-kamau", dry_run=False)
print(sorted(p.name for p in folder.iterdir()))

import csv, io
from collections import defaultdict

# Imagine this came from an exported M-Pesa statement or sales system
data = """date,branch,product,amount
2026-10-01,Thika,Unga,5400
2026-10-01,Ruiru,Sugar,3000
2026-10-02,Thika,Sugar,4500
2026-10-02,Ruiru,Unga,7200
2026-10-03,Thika,Milk,2600
"""

by_branch = defaultdict(int)
by_product = defaultdict(int)
for row in csv.DictReader(io.StringIO(data)):
    amount = int(row["amount"])
    by_branch[row["branch"]] += amount
    by_product[row["product"]] += amount

print("Sales by branch:")
for branch, total in sorted(by_branch.items(), key=lambda x: -x[1]):
    print(f"  {branch:<8} KSh {total:>8,}")
print("Best product:", max(by_product, key=by_product.get))

# Write the summary to a new CSV file
with open("summary.csv", "w", newline="", encoding="utf-8") as f:
    w = csv.writer(f)
    w.writerow(["branch", "total"])
    w.writerows(sorted(by_branch.items()))
print(open("summary.csv", encoding="utf-8").read())

from openpyxl import Workbook
from openpyxl.styles import Font
from openpyxl.chart import BarChart, Reference

wb = Workbook()
ws = wb.active
ws.title = "Sales"
ws.append(["Branch", "Total (KSh)"])
for branch, total in [("Thika", 12500), ("Ruiru", 10200)]:
    ws.append([branch, total])
ws["A1"].font = ws["B1"].font = Font(bold=True)

chart = BarChart()
chart.title = "Sales by branch"
chart.add_data(Reference(ws, min_col=2, min_row=1, max_row=3), titles_from_data=True)
chart.set_categories(Reference(ws, min_col=1, min_row=2, max_row=3))
ws.add_chart(chart, "D2")

wb.save("weekly-report.xlsx")

import requests

response = requests.get("https://api.example.com/rates", params={"base": "USD"}, timeout=10)
response.raise_for_status()           # raises an error for 4xx/5xx responses
rates = response.json()
print(rates["KES"])

import json, time

def fake_get(url, params=None, timeout=10):
    """Pretend API: returns JSON text like a real web service would."""
    time.sleep(0.1)
    return json.dumps({"base": "USD", "rates": {"KES": 129.25, "UGX": 3700.5, "TZS": 2650.0}})

def get_rate(currency):
    try:
        data = json.loads(fake_get("https://api.example.com/latest", params={"base": "USD"}))
        return data["rates"][currency]
    except KeyError:
        return None

for cur in ["KES", "UGX", "XYZ"]:
    rate = get_rate(cur)
    print(cur, "->", rate if rate is not None else "not available")

import smtplib, os
from email.message import EmailMessage

msg = EmailMessage()
msg["Subject"] = "Weekly sales report"
msg["From"] = "reports@example.co.ke"
msg["To"] = "manager@example.co.ke"
msg.set_content("Hello, the weekly report is attached.")
msg.add_attachment(open("weekly-report.xlsx", "rb").read(), maintype="application", subtype="octet-stream", filename="weekly-report.xlsx")

with smtplib.SMTP_SSL("smtp.example.co.ke", 465) as server:
    server.login(os.environ["SMTP_USER"], os.environ["SMTP_PASSWORD"])
    server.send_message(msg)