code: def get_student_by_email(self, email, students=None):
          
          if students is None:
              students = self.get_students()
  
          email = email.lower()
          for student in students:
              if student['accountEmail'].lower() == email:
                  return student['studentId'], student
          return None, None
docs: Get a student based on an email address.
  
          Calls ``self.get_students()`` to get list of all students,
          if not passed as the ``students`` parameter.
  
          Args:
              email (str): student email
              students (list): dictionary of students to search, default: None
                  When ``students`` is unspecified, all students in gradebook
                  are retrieved.
  
          Raises:
              requests.RequestException: Exception connection error
              ValueError: Unable to decode response content
  
          Returns:
              tuple: tuple of student id and student dictionary.