Enhancement in v1.13.2

For PDF documents, check the bool doc.isFormPDF. It is True if an object of type /AcroForm and at least one form field exist. Form fields are a special Annotation object type: "Widget". Scan through the annotations of a Page like this:

for page in doc:
    annot = page.firstAnnot
    while annot:
        if annot.type[0] != fitz.ANNOT_WIDGET: # form field type is (19, 'Widget')
            annot = annot.next                 # last annot has no "next"
            continue
        print(annot.widget_type, annot.widget_name, annot.widget_text)
        annot = annot.next

In this version, only text form field (annot.widget_type == (3, 'Tx')) content is shown. In later versions we will also detect checked buttons, selected dropdown items, etc.