initialize common package

csst/common/fileio.py

+from astropy.io import fits
+
+
+class Header(fits.Header):
+    """ a custom Header class
+
+    Conf
+    ----
+    https://docs.astropy.org/en/stable/io/fits/api/headers.html#astropy.io.fits.Header
+
+    """
+
+    def __init__(self, cards=[], copy=False):
+        super(Header, self).__init__(cards=cards, copy=copy)
+
+
+test_hdr_str = """
+SIMPLE  =                    T / conforms to FITS standard
+BITPIX  =                    8 / array data type
+NAXIS   =                    0 / number of array dimensions
+EXTEND  =                    T
+"""
+
+if __name__ == "__main__":
+
+    hdr = Header.fromstring(test_hdr_str, sep='\n')
+    print(hdr['SIMPLE'], hdr['BITPIX'], len(hdr))