Steel Quotation Assistant

A command-line quotation generator for reinforcing steel sales. It builds multi-item quotations, prices each line by grade and size, applies VAT, assigns sequential quotation numbers, stores everything in SQLite, and exports a formatted text quotation.

Status: early-stage, functional. Command-line interface only. No external dependencies.

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Problem

Preparing a rebar quotation manually means looking up the price for each grade and size, multiplying by quantity, adding VAT, numbering the document, and keeping a record of what was sent to whom. Done by hand, this is slow and error-prone, and there is no structured history of customers, projects, and quotations.

Solution

A small Python application that captures customer, project, and line items once, computes the totals, persists the record in a local database, and produces a clean text quotation ready to send.

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Features

• Multiple line items per quotation (grade, size, quantity in tons)
• Automatic unit pricing by grade and size from a central price list
• Subtotal, VAT (15%), and grand total
• Sequential quotation numbering (Q-000001, Q-000002, ...) derived from the database
• Quotation date and a 7-day validity date
• SQLite persistence: customers, projects, quotations, quotation items
• Text export of each quotation to quotations/
• Listing of previously exported quotations

Supported grades: 60, 80 Supported sizes (mm): 10, 12, 14, 16, 18, 20, 25, 32

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Architecture

Each module has a single responsibility.

app.py                     User interface: menu, input, program flow. No SQL, no business logic.
database.py                SQLite connection, schema creation, insert and lookup functions.
models/
    item.py                Item dataclass: grade, size, quantity, unit price, line total.
    quotation.py           Quotation: items, totals, dates, numbering, text formatting.
services/
    price_service.py       Price list and price lookup.
data/                      SQLite database (created at runtime, ignored by git).
quotations/                Exported text quotations (created at runtime, ignored by git).

Database schema

Table	Purpose
customers	Customer name
projects	Project name, linked to a customer
quotations	Quotation number, dates, subtotal, VAT, grand total, linked to customer and project
quotation_items	Grade, size, quantity, unit price, total, linked to a quotation

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Technology

• Python 3.9 or later
• Standard library only: sqlite3, dataclasses, pathlib, datetime

requirements.txt is intentionally empty.

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Installation

git clone https://github.com/UKDean/SteelQuotationAssistant.git
cd SteelQuotationAssistant
python app.py

No virtual environment or package installation is required, although a virtual environment is recommended if you extend the project.

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Usage

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      Steel Quotation Assistant
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1. Create New Quotation
2. View Quotations
3. Exit

1. Choose 1, enter the customer name and project name.
2. Enter each item: grade (60 or 80), size (mm), and quantity in tons. Invalid grade or size combinations are rejected and you are prompted again.
3. Answer n when finished. The quotation is printed, saved to the database, and exported to quotations/quotation_N.txt.
4. Choose 2 to list exported quotations.

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Configuration

Prices live in services/price_service.py as a PRICE_LIST dictionary keyed by grade and then size. Update this dictionary to reflect current pricing before use. VAT is fixed at 15% in models/quotation.py.

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Testing

The suite covers the price lookup, quotation totals, VAT, validity dates, text output, and SQLite persistence. Database tests run against a temporary database, so they never touch data/steel.db.

python -m pip install pytest
python -m pytest -v

30 tests, all passing.

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Known Issues

Quotation numbers can come from two different sources: database.get_next_quotation_number() reads from the database, while Quotation.get_next_number() counts exported text files. app.py uses the database, but the file-based fallback still runs when a Quotation is created without an explicit number, which can produce a duplicate number. Consolidating on the database as the single source of truth is pending.

Roadmap

Planned, not yet implemented:

• Externalize the price list and VAT rate into a configuration file
• Customer and project lookup instead of creating a new record per quotation
• PDF export
• Graphical interface

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License

Released under the MIT License.