pangoLayoutSetText(object, text, length = -1)objecttextlengthtext, in bytes. -1 indicates that
the string is and the length should be
calculated. The text will also be truncated on
encountering a nul-termination even when length is
positive.pangoLayoutSetMarkup or pangoLayoutSetMarkupWithAccel on
layout before, you may want to call pangoLayoutSetAttributes to clear
the attributes set on the layout from the markup as this function does not
clear attributes.