ns
    may raise UnsupportedOperation when operations they do not support are
    called.

    The basic type used for binary data read from or written to a file is
    bytes. Other bytes-like objects are accepted as method arguments too.
    Text I/O classes work with str data.

    Note that calling any method (even inquiries) on a closed stream is
    undefined. Implementations may raise OSError in this case.

    IOBase (and its subclasses) support the iterator protocol, meaning
    that an IOBase object can be iterated over yielding the lines in a
    stream.

    IOBase also supports the :keyword:`with` statement. In this example,
    fp is closed after the suite of the with statement is complete:

    with open('spam.txt', 'r') as fp:
        fp.write('Spam and eggs!')
    c