custom_schema.py

"""Custom fields on top of a preset, fields injected into every line-item row, and saving
the combination so later calls are one argument.

    python examples/custom_schema.py invoice.pdf
"""

import sys

from visionapi import ConflictError, VisionAPI, rows, unwrap, value

path = sys.argv[1] if len(sys.argv) > 1 else "invoice.pdf"
vision = VisionAPI()

schema = {
    # Plain form: the string is the description. Descriptions are the prompt — the more
    # precisely you say what you want, the better the extraction.
    "machine_serial": 'Serial number of the machine being invoiced, without the "SN:" prefix',

    # Typed form. Numbers come back as JSON numbers, dates as ISO YYYY-MM-DD.
    "total_net": {"type": "number", "description": "Total before tax"},
    "is_paid": {"type": "boolean", "description": "Whether the invoice is stamped or marked PAID"},
    "reference_numbers": {"type": "array", "description": "All reference numbers", "items": "string"},

    # "line_item" is reserved: these become extra columns on every row of the preset's
    # line-item array. Only meaningful with a preset that has line items; with a bare
    # custom schema there is nothing to inject into.
    "line_item": {"lot_number": "The lot number printed on this line, if present"},
}

res = vision.analyze(file=path, preset="invoice", schema=schema)
result = res["result"]

print("serial:", value(result, "machine_serial"))
print("net total:", value(result, "total_net"))
print("paid:", value(result, "is_paid"))

for row in rows(result, "line_item"):
    line = unwrap(row)
    print(
        f"  {line.get('quantity') or '?'} × {line.get('description') or '(no description)'}"
        f" = {line.get('amount') or '?'}  [lot {line.get('lot_number') or '—'}]"
    )

# Save it, and the next call is schema_name="our-invoices". The definition is compiled
# before it is stored, so an invalid schema fails here rather than on the first extraction
# that uses it.
try:
    vision.create_schema("our-invoices", preset="invoice", schema=schema)
    print('\nsaved as "our-invoices"')
except ConflictError:
    vision.update_schema("our-invoices", preset="invoice", schema=schema)
    print('\nupdated "our-invoices"')

again = vision.analyze(file=path, schema_name="our-invoices")
print("same fields via the saved schema:", len(again["result"]))