Add method to print values to stdout

Added __str__ method to SystemInformation class.

SystemInformation.py

@@ -143,6 +143,19 @@ class SystemInformation:
             f.write('HDD:\t{}\n'.format(hdd_string))
             f.write('OS:\t{}\n'.format(self.os))
 
+    def __str__(self):
+        part_strs = []
+        for p in self.hdd_free:
+            part_strs.append('{} {:.2f}GB free'.format(p[0], p[1]/(1024**3)))
+        hdd_string = ', '.join(part_strs)
+        return '\n'.join(['CPU:\t{}'.format(self.cpu),
+                          'Video:\t{}'.format(self.graphics),
+                          'RAM:\t{:.2f}GB total'
+                          .format(self.total_ram/(1024**3)),
+                          'HDD:\t{}'.format(hdd_string),
+                          'OS:\t{}'.format(self.os)])
+
 if __name__ == '__main__':
     sys = SystemInformation()
     sys.save()
+    print(sys)