pango.FontFamily — an object representing a family of related font faces.
The pango.FontFamily 
object is used to represent a family of related font faces. The faces in a
family share a common design, but differ in slant, weight, width and other
aspects. A list of pango.FontFamily 
objects can be retrieved  from a pango.Context
object using the pango.Context.list_families() 
method and from a pango.FontMap
object using the pango.FontMap.list_families() 
method.
    def list_faces()| Returns : | a list of pango.FontFaceobjects. | 
The list_faces() method returns a list
of the different pango.FontFace
object that make up the font family>. The faces in a family share a common
design, but differ in slant, weight, width and other aspects.
    def get_name()| Returns : | the name of the family. | 
The get_name() method returns a string
containing the name of the font family. The name is unique among all fonts
for the font backend and can be used in a pango.FontDescription 
to specify that a face from this family is desired.
    def is_monospace()| Returns : | Trueif the font family is
	  monospace. | 
The is_monospace() method returns
      True if the font family describes a monospace
      font. A monospace font is a font designed for text display where the
      the characters form a regular grid. For Western languages this would
      mean that the advance width of all characters are the same, but this
      categorization also includes Asian fonts which include double-width
      characters: characters that occupy two grid cells. The best way to
      find out the grid-cell size is to call the get_approximate_digit_width()
      method, since the results of the get_approximate_char_width()