API Example

pdfforms v2.0 introduces a python API for filling pdf forms similar to the command-line interface. This can be useful for preprocessing and formatting data values used to populate the forms.

For example, when loading a LibreOffice Calc spreadsheet with pyexcel-ods, values formatted as currency are read as a string with a floating point number followed by a space and a currency designation, so: '18746.3048283886 USD'. Since a more friendly representation may be desired, the api provides for successive application of a chain of formatting functions. Two such functions are provided with the library.

Here is a concrete example which I use to fill my tax forms from a LibreOffice Calc spreadsheet. It parses US and Israel currency designations, rounds floating-point numbers, and represents negative numbers with parentheses rather than a minus sign.

"fill pdf tax forms"
import sys

from pdfforms import pdfforms


def main(data_file):
    "do it"
    for filepath in pdfforms.fill_pdfs(
        data_file,
        sheet_name="f1040",
        value_transforms=[parse_currency, format_number],
    ):
        print(filepath)


def parse_currency(value):
    "try to read a number with a currency mark"
    try:
        if value.endswith((" USD", " ILS")):
            return float(value.split()[0])
    except (AttributeError, ValueError):
        pass
    return value


def format_number(value):
    try:
        format_str = "({:,})" if value < 0 else "{:,}"
        return format_str.format(round(abs(value)))
    except (TypeError, ValueError):
        return value


if __name__ == "__main__":
    main(sys.argv[1])