A script to fillout/annotate a pdf form

pdf_form_editor.py

from pdfrw import PdfReader, PdfWriter, PdfDict, PdfObject
ANNOT_KEY = '/Annots'
ANNOT_FIELD_KEY = '/T'
ANNOT_VAL_KEY = '/V'
ANNOT_RECT_KEY = '/Rect'
SUBTYPE_KEY = '/Subtype'
WIDGET_SUBTYPE_KEY = '/Widget'

def main():
    pdf = PdfReader('qpdf.pdf')
    pdf.Root.AcroForm.update(PdfDict(NeedAppearances=PdfObject('true')))
    pages = pdf.pages
    keys = []
    for page in range(len(pages)):
        annotations = pdf.pages[page]['/Annots']
        for annotation in annotations:
            if annotation[SUBTYPE_KEY] == WIDGET_SUBTYPE_KEY:
                if annotation[ANNOT_FIELD_KEY]:
                    key = annotation[ANNOT_FIELD_KEY][1:-1]
                    keys.append(key)
                    #annotation.update(PdfDict(AP='{}'.format('69'), V='{}'.format('69')))
    PdfWriter().write('test.pdf', pdf)
    with open('fields.txt', 'w') as f:
        for key in keys:
            f.write(key)
            f.write('\n')

if __name__ == '__main__':
    main()