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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _convert_string_array(data, encoding, errors, itemsize=None):
 """ we take a string-like that is object dtype and coerce to a fixed size string type Parameters data : a numpy array of object dtype encoding : None or string-encoding errors : handler for encoding errors itemsize : integer, optional, defaults to the max length of the strings Returns ------- data in a fixed-length string dtype, encoded to bytes if needed """


    # encode if needed
    if encoding is not None and len(data):
        data = Series(data.ravel()).str.encode(
            encoding, errors).values.reshape(data.shape)

    # create the sized dtype
    if itemsize is None:
        ensured = ensure_object(data.ravel())
        itemsize = max(1, libwriters.max_len_string_array(ensured))

    data = np.asarray(data, dtype="S{size}".format(size=itemsize))
    return data