<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def load_shx(self, shapefile_name):

 """
 Attempts to load file with .shx extension as both lower and upper case
 """

        shx_ext = 'shx'
        try:
            self.shx = open("%s.%s" % (shapefile_name, shx_ext), "rb")
        except IOError:
            try:
                self.shx = open("%s.%s" % (shapefile_name, shx_ext.upper()), "rb")
            except IOError:
                pass