codecs_bom_create.py

#1/usr/bin/env python

# this is from The Python
# Standard Library by example
# ISBN13: 9780321767349

import codecs
from codecs_to_hex import to_hex

# Pick the nonnative version of UTF-16 encoding
if codecs.BOM_UTF16 == codecs.BOM_UTF16_BE:
    bom = codecs.BOM_UTF16_LE
    encoding = 'utf_16_le'
else:
    bom = codecs.BOM_UTF16_BE
    encoding = 'utf_16_be'

print 'Native order     :', to_hex(codecs.BOM_UTF16, 2)
print 'Selected order   :', to_hex(bom, 2)

# Encode the text.
encoded_text = u'pi: \u03c0'.encode(encoding)
print '{:14}: {}'.format(encoding, to_hex(encoded_text, 2))

with open('nonnative-encoded.txt', mode='wb') as f:
    # Write the selected byte-order marker. It is not included
    # in the encoded text because the byte order was given
    # explicitly when selecting the encoding.
    f.write(bom)
    # Write the byte string for the encoded text.
    f.write(encoded_text)