# duck_typing.py

# duck_typing.py

from io import StringIO

def write(message, stream):
  stream.write(message)
  stream.seek(0)

stream = StringIO()
# file_ = open('/tmp/test.txt', 'w')

write(u'hello', stream)
# write(u'hello', file_)

print(stream.read())
# print(file_.read())