Here we collect miscellaneous notes that are helpful when reading or working with the specs.

FITS BINTABLE TFORM data type codes

The valid FITS BINTABLE TFORM data type codes are given in this table in the FITS standard paper in table 18

Information on how to use it correctly via CFITSIO is here

For, there’s these dicts to translate FITS BINTABLE TFORM codes to Numpy dtype codes:

>>> from import FITS2NUMPY, NUMPY2FITS
{'J': 'i4', 'I': 'i2', 'L': 'i1', 'E': 'f4', 'M': 'c16', 'B': 'u1', 'K': 'i8', 'C': 'c8', 'D': 'f8', 'A': 'a'}
{'i1': 'L', 'c16': 'M', 'i4': 'J', 'f2': 'E', 'i2': 'I', 'b1': 'L', 'i8': 'K', 'u8': 'K', 'u1': 'B', 'u4': 'J', 'u2': 'I', 'c8': 'C', 'f8': 'D', 'f4': 'E', 'a': 'A'}

But normally you never should have to manually handle these dtypes from Python. or astropy.table.Table will read and write the TFORM FITS header keys correctly for you.