code: def get_assemblies(names=[]):
      
  
      if names == []:
          names = get_assembly_names()
      return {a['name']: a for a in (get_assembly(n) for n in names)}
docs: read specified assemblies, or all if none specified, returning a
      dictionary of assembly-name: assembly.  See get_assembly()
      function for the structure of assembly data.
  
      >>> assemblies = get_assemblies(names=['GRCh37.p13'])
      >>> assy = assemblies['GRCh37.p13']
  
      >>> assemblies = get_assemblies()
      >>> 'GRCh38.p2' in assemblies
      True