`astropy.io.fits.hdu.base:_ValidHDU.add_datasum`

source: /astropy/io/fits/hdu/base.py :1240

Signature

def add_datasum ( self , when = None , datasum_keyword = DATASUM )

Summary

Add the DATASUM card to this HDU with the value set to the checksum calculated for the data.

Parameters

when : str, optional: Comment string for the card that by default represents the time when the checksum was calculated
datasum_keyword : str, optional: The name of the header keyword to store the datasum value in; this is typically 'DATASUM' per convention, but there exist use cases in which a different keyword should be used

Returns

checksum : int: The calculated datasum

Notes

For testing purposes, provide a when argument to enable the comment value in the card to remain consistent. This will enable the generation of a CHECKSUM card with a consistent value.

Aliases

astropy.io.fits.convenience._ValidHDU.add_datasum