|AHELP for CIAO 4.2||
Delete a keyword from a crate.
- crate - input crate
- keyid - key name or number, where the first key is numbered 0
The delete_key command removes the specified keyword from the crate. The print_key_names command ("ahelp print_key_names") lists all the keywords in the file with the corresponding numbers.
The command returns a "1" if the keyword is successfully deleted. The keyword is only deleted from the data in the crate; it's not removed from the input file. The write_file command ("ahelp write_file") can be used to save the modified crate to a file.
>>> cr = read_file("evt2.fits") >>> print(get_key_names(cr)) ['TELESCOP' 'INSTRUME' 'DETNAME' 'FILTER' 'CHANTYPE' 'DETCHANS'...] >>> delete_key(cr, "FILTER") 1 >>> key_exists(cr, "FILTER") 0 >>> write_file(cr, "nofilt.fits") 1
Delete the FILTER keyword from the crate, then use the key_exists command to confirm it has been deleted. Write the crate to nofilt.fits.
>>> cr = read_file("evt2.fits") >>> delete_key(cr, 35) 1 >>> key_exists(cr, "OBS_ID") 0 >>> write_file(cr, "edit.fits") 1
Delete keyword number 35 - the OBS_ID keyword in this file - from the crate, then write the crate to file edit.fits.
See the bug pages on the CIAO website for an up-to-date listing of known bugs.