Retrieves one or more attributes of a problem.

p = xpress.problem ()
p.read ("example.lp")
print (p.getAttrib ('cols'), "columns and ",
       p.getAttrib ('rows'), "rows")
prob_attrib = p.getAttrib ()
attr_subset = p.getAttrib (['cols', 'rows'])

This function can be passed either a single attribute name, whose value will be returned, or a list of attribute names, in which case the return value is a dictionary associating each key in the list with its value. If no argument is provided, a dictionary containing all attributes of the problem will be returned.