parameters: (self, policy_id)
return_statement: return res['tuples'][0]
docstring: Returns the security policy that has a policy_id matching the input
          specified by the user.
docstring_summary: Returns the security policy that has a policy_id matching the input
          specified by the user.
docstring_tokens: Returns the security policy that has a policy_id matching the input specified by the user .
function: def find_security_policy_by_id(self, policy_id):
          '''
          Returns the security policy that has a policy_id matching the input
          specified by the user.
          '''
          query = ('SELECT policy_id, policy, policy_type, grantee, grantor, '
                   'repo_base, repo, table_name '
                   'FROM dh_public.policy WHERE policy_id = %s')
          params = (policy_id,)
          res = self.execute_sql(query, params)
  
          # return None if the list is empty
          if not res['tuples']:
              return None
  
          # else, return the policy
          return res['tuples'][0]
function_tokens: def find_security_policy_by_id ( self , policy_id ) : query = ( 'SELECT policy_id, policy, policy_type, grantee, grantor, ' 'repo_base, repo, table_name ' 'FROM dh_public.policy WHERE policy_id = %s' ) params = ( policy_id , ) res = self . execute_sql ( query , params ) # return None if the list is empty if not res [ 'tuples' ] : return None # else, return the policy return res [ 'tuples' ] [ 0 ]