gs123 4.0.1

Barcode to URN Conversion

from gs123.conversion import BarcodeConverter

# Parse a GS1 barcode (GTIN + Serial + Expiry + Lot)
bc = BarcodeConverter(
    "(01)20614141073461(21)0000010020(17)261231(10)LOTA1",
    company_prefix_length=7,
)

print(bc.epc_urn)          # urn:epc:id:sgtin:0614141.207346.10020
print(bc.gtin14)           # 20614141073461
print(bc.serial_number)    # 10020
print(bc.lot)              # LOTA1
print(bc.expiration_date)  # 261231

URN to Barcode Conversion

from gs123.conversion import URNConverter

converter = URNConverter("urn:epc:id:sgtin:0614141.207346.10020")

# Get a barcode string with lot and expiry
barcode = converter.get_barcode_value(
    lot="LOTA1",
    expiration="261231",
    parenthesis=True,
)
print(barcode)  # (01)20614141073461(21)10020(17)261231(10)LOTA1

Data Matrix Barcode Generation

Generate GS1 Data Matrix barcodes for pharmaceutical serialization, shipping labels, and traceability. Uses the ppf.datamatrix library (MIT license) for pure-Python encoding — no native libraries or Ghostscript required.

From a GS1 element string:

from gs123.datamatrix import GS1DataMatrix

dm = GS1DataMatrix("(01)20614141073461(21)0000010020(17)261231(10)LOTA1")

# Save as SVG (vector — crisp at any size, no extra deps)
dm.save_svg("barcode.svg", scale=10)

# Save as PNG (requires Pillow)
dm.save_png("barcode.png", scale=10)

# Get raw bytes for embedding in web pages, PDFs, etc.
svg_str = dm.svg()
png_bytes = dm.png()

From an EPC URN:

from gs123.datamatrix import GS1DataMatrix

dm = GS1DataMatrix.from_urn(
    "urn:epc:id:sgtin:0614141.207346.10020",
    company_prefix_length=7,
    lot="LOTA1",
    expiration="261231",
)
dm.save_png("from_urn.png", scale=12)

From a scanned barcode (round-trip):

from gs123.datamatrix import GS1DataMatrix

# Parse a scanned barcode and regenerate a clean Data Matrix
dm = GS1DataMatrix.from_barcode(
    "(01)20614141073461(21)0000010020(17)261231(10)LOTA1",
    company_prefix_length=7,
)
dm.save_svg("regenerated.svg")

# Override the lot for a repack scenario
dm = GS1DataMatrix.from_barcode(
    "(01)20614141073461(21)0000010020(17)261231(10)LOTA1",
    company_prefix_length=7,
    lot="NEWLOT99",
)

SSCC-18 (shipping containers):

from gs123.datamatrix import GS1DataMatrix

dm = GS1DataMatrix.from_urn(
    "urn:epc:id:sscc:0614141.1234567890",
    company_prefix_length=7,
)
dm.save_png("sscc_label.png", scale=10)

Batch generation:

from gs123.datamatrix import GS1DataMatrix

for serial in range(10001, 10021):
    urn = f"urn:epc:id:sgtin:0614141.207346.{serial}"
    dm = GS1DataMatrix.from_urn(
        urn,
        company_prefix_length=7,
        lot="BATCH2026A",
        expiration="271231",
    )
    dm.save_png(f"label_{serial}.png", scale=10)

Inspect the module matrix:

from gs123.datamatrix import GS1DataMatrix

dm = GS1DataMatrix("(01)20614141073461(21)0000010020")
rows, cols = dm.symbol_size  # (22, 22)
matrix = dm.matrix           # list of lists, 1=dark 0=light

# ASCII art
for row in matrix:
    print("".join("██" if v else "  " for v in row))