University of Arizona, Department of Computer Science

CSc 120: List to Dictionary

Expected Behavior

Write a function list2dict(list2d) that behaves as follows. Its argument list2d is a 2D list (i.e., list of lists) of strings. It returns a dictionary whose keys are the first elements of each row, and where each such key is mapped to the list consisting of the remaining elements of that row.

Examples

  1. Let x1 be the following list of lists: 
    [ [ 'aa', 'bb', 'cc', 'dd' ],
  [ 'ee', 'ff', 'gg', 'hh', 'ii', 'jj' ],
  [ 'kk', 'll', 'mm', 'nn' ] ]

    Then list2dict(x1) returns the dictionary 

    { 'aa' : [ 'bb', 'cc', 'dd' ],
  'ee' : [ 'ff', 'gg', 'hh', 'ii', 'jj' ],
  'kk' : [ 'll', 'mm', 'nn' ]
}

  2. Let x2 be the following list of lists: 
    [ [ 'aa', 'bb' ],
  [ 'cc', 'dd' ],
  [ 'ee', 'ff' ],
  [ 'gg', 'hh' ],
  [ 'kk', 'll' ] ]

    Then list2dict(x2) returns the dictionary 

    { 'aa' : [ 'bb' ],
  'cc' : [ 'dd' ],
  'ee' : [ 'ff' ],
  'gg' : [ 'hh' ],
  'kk' : [ 'll' ]
}

  3. Let x3 be the following list of lists: 
    [ [ 'aa', 'bb' ],
  [ 'cc', 'dd', 'ee' ],
  [ 'ff', 'gg' ],
  [ 'hh', 'ii', jj' ],
  [ 'kk' ] ]

    Then list2dict(x3) returns the dictionary 

    { 'aa' : [ 'bb' ],
  'cc' : [ 'dd', 'ee' ],
  'ff' : [ 'gg' ],
  'hh' : [ 'ii', 'jj' ],
  'kk' : []
}