pkgprint 0.1.0

Print and packaging math utilities for developers

pkgprint

Print and packaging math utilities for Python developers.

pkgprint is a zero-dependency Python library that handles the fiddly maths behind print and packaging production: unit conversions, colour model translations, standard paper and box sizes, and bleed/margin arithmetic.

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Installation

pip install pkgprint

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Quick Start

import pkgprint

# Get A4 dimensions and convert to inches
w, h = pkgprint.paper_size("A4")
print(pkgprint.mm_to_inches(w), pkgprint.mm_to_inches(h))
# → 8.267716535433071 11.692913385826772

# Add 3 mm bleed to a business card
bleed_w, bleed_h = pkgprint.add_bleed(89, 51, bleed_mm=3)
print(bleed_w, bleed_h)
# → 95 57

# Convert a brand colour from CMYK to RGB
rgb = pkgprint.cmyk_to_rgb(0, 100, 100, 0)   # Pantone-ish red
print(rgb)
# → (255, 0, 0)

# Convert back from hex to RGB
print(pkgprint.hex_to_rgb("#FF5733"))
# → (255, 87, 51)

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API Reference

units — Measurement Conversions

Function	Description
mm_to_inches(mm)	Millimetres → inches
inches_to_mm(inches)	Inches → millimetres
mm_to_points(mm)	Millimetres → typographic points (1 pt = 1/72 in)
points_to_mm(points)	Points → millimetres
dpi_to_ppi(dpi)	DPI → PPI (semantic alias, same unit)
ppi_to_dpi(ppi)	PPI → DPI (semantic alias, same unit)

import pkgprint

pkgprint.mm_to_inches(25.4)     # → 1.0
pkgprint.inches_to_mm(8.5)      # → 215.9  (US Letter width)
pkgprint.mm_to_points(210)      # → 595.28 (A4 width in points)
pkgprint.points_to_mm(72)       # → 25.4
pkgprint.dpi_to_ppi(300)        # → 300
pkgprint.ppi_to_dpi(96)         # → 96

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color — Colour Model Conversions

Function	Description
cmyk_to_rgb(c, m, y, k)	CMYK → RGB. Accepts 0–100 or 0–1 inputs.
rgb_to_cmyk(r, g, b)	RGB → approximate CMYK (device-independent).
hex_to_rgb(hex_code)	CSS hex string → RGB tuple. Supports #fff shorthand.
rgb_to_hex(r, g, b)	RGB tuple → uppercase CSS hex string.

import pkgprint

pkgprint.cmyk_to_rgb(0, 100, 100, 0)   # → (255, 0, 0)  red
pkgprint.cmyk_to_rgb(0, 1, 1, 0)       # → (255, 0, 0)  same, 0–1 range
pkgprint.rgb_to_cmyk(0, 0, 255)         # → (100.0, 100.0, 0.0, 0.0)  blue
pkgprint.hex_to_rgb("#FF5733")          # → (255, 87, 51)
pkgprint.hex_to_rgb("#fff")             # → (255, 255, 255)  shorthand ok
pkgprint.rgb_to_hex(255, 87, 51)        # → '#FF5733'

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paper — Standard Sizes

Function	Description
paper_size(name)	(width, height) in mm for a named paper size. Case-insensitive.
list_paper_sizes()	Sorted list of all supported paper size names.
box_size(style)	(length, width, height) in mm for a named packaging box. Case-insensitive.

Supported paper sizes: ISO A0–A8, B0–B6, C4–C6 (envelopes), Letter, Legal, Tabloid, Executive, ANSI A–E, Business Card, Postcard, and more.

Supported box styles: RSC Small/Medium/Large, Mailer A4/A5, Gift Small/Medium/Large, Tuck Small/Medium/Large.

import pkgprint

pkgprint.paper_size("A4")           # → (210, 297)
pkgprint.paper_size("letter")       # → (216, 279)  case-insensitive
pkgprint.box_size("RSC Medium")     # → (305, 229, 152)
pkgprint.list_paper_sizes()         # → ['A0', 'A1', ..., 'Tabloid', ...]

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print_specs — Print Production Math

Function	Description
add_bleed(width, height, bleed_mm=3)	Trim size → artwork size with bleed on all four sides.
safe_margin(width, height, margin_mm=5)	Trim size → safe content area (removes margins).
trim_size(width, height, bleed_mm=3)	Artwork size (with bleed) → trim size.

import pkgprint

# Business card: 89 × 51 mm → with 3 mm bleed → 95 × 57 mm
pkgprint.add_bleed(89, 51)               # → (95, 57)

# A4 safe content area with 5 mm margins
pkgprint.safe_margin(210, 297, margin_mm=5)  # → (200, 287)

# Reverse: what is the trim size of a 220 × 307 mm file with 5 mm bleed?
pkgprint.trim_size(220, 307, bleed_mm=5)     # → (210, 297)

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Build & Publish

# Install build tools
pip install build twine

# Build source + wheel
python -m build

# Test publish (TestPyPI)
twine upload --repository testpypi dist/*

# Real publish
twine upload dist/*

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Running Tests

pip install pytest
pytest

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License

MIT — see LICENSE.