import pdfrw

def setField(template_pdf,field,value):
    ANNOT_KEY = '/Annots'
    ANNOT_FIELD_KEY = '/T'
    ANNOT_VAL_KEY = '/V'
    ANNOT_RECT_KEY = '/Rect'
    SUBTYPE_KEY = '/Subtype'
    WIDGET_SUBTYPE_KEY = '/Widget'
    annotations = template_pdf.pages[0][ANNOT_KEY]
    for annotation in annotations:
        if annotation[SUBTYPE_KEY] == WIDGET_SUBTYPE_KEY:
            if annotation[ANNOT_FIELD_KEY]:
                key = annotation[ANNOT_FIELD_KEY][1:-1]
                if key==field:
                    annotation.update(pdfrw.PdfDict(V=value))

#open
tp = pdfrw.PdfReader("Downloads/D&D_colored_halfpage redesigned_Template2.pdf")

#set field
setField(tp,"Name01","Alex")

#save
pdfrw.PdfWriter().write("test.pdf", tp)