_task_name_ = string_kw(default="extract_headerlet")
filename = string_kw(default="", comment="Input file name")
output = string_kw(default="", comment="Output headerlet FITS filename")
extnum = integer_or_none_kw(default=None, comment="FITS extension number of headerlet")
hdrname = string_kw(default="", comment="Unique name(HDRNAME) for headerlet")
clobber = boolean_kw(default=True, comment= "Overwrite existing headerlet FITS file?")
logging = boolean_kw(default=False, comment= "Enable logging to a file")