diff --git a/README.md b/README.md
index 5a8515c..cbb982e 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@
 ![download](https://pepy.tech/badge/cqu-kb)
 ![Upload Python Package](https://github.com/CQU-AI/cqu-kb/workflows/Upload%20Python%20Package/badge.svg)
 
-cqu-kb 是一个基于python3的，导出重庆大学课程表的第三方工具。
+cqu-kb 是一个基于python3的，导出重庆大学**本科生和研究生**课程表的第三方工具。
 
 
 ## 1. 安装和使用
@@ -37,3 +37,4 @@ cqu-kb 是一个基于python3的，导出重庆大学课程表的第三方工具
 2. 本程序不存储用户的帐号，密码。
 3. 本程序不存储任何人的课表，所有的数据来自于重庆大学教务网。
 4. 本程序依赖于[`cqu-jxgl`](https://github.com/CQU-AI/cqu-jxgl)
+5. 在订阅使用时，由于直接使用http的get，存在一定的隐私泄露风险，详见 #5 。
\ No newline at end of file
diff --git a/setup.py b/setup.py
index 5d60c7f..16e7c7a 100644
--- a/setup.py
+++ b/setup.py
@@ -2,7 +2,7 @@
 
 from setuptools import setup, find_packages
 
-version = "0.2.2"
+version = "0.3.0"
 
 # Read the contents of README file
 source_root = Path(".")
diff --git a/src/cqu-kb-subscription/app.py b/src/cqu-kb-subscription/app.py
index 14ec8e6..765e2cc 100644
--- a/src/cqu-kb-subscription/app.py
+++ b/src/cqu-kb-subscription/app.py
@@ -5,49 +5,72 @@
 from flask import Flask, send_from_directory, Response, abort, redirect
 
 from cqu_kb.__main__ import server_main
+from cqu_kb.utils import is_grad, is_under_grad
+
 
 app = Flask(__name__)
 
 base_dir = Path("--enter-path-here--")
 
 
-@app.route('/')
+@app.route("/")
 def main_repo():
-    return redirect('https://github.com/CQU-AI/cqu-kb')
+    return redirect("https://github.com/CQU-AI/cqu-kb")
 
 
-@app.route('/<username>/<password>')
+@app.route("/<username>/<password>")
 def get_ical(username, password):
-    if not username.isdigit() or len(username) != 8 or not username.startswith("20"):
-        abort(Response(f"Error: Invalid username. \n"
-                       f"Please check the availability of your account and password.".replace("\n", '<br />')))
+    if (not is_under_grad(username)) and (not is_grad(username)):
+        abort(
+            Response(
+                f"Error: Invalid username. \n"
+                f"Please check the availability of your account and password.".replace(
+                    "\n", "<br />"
+                )
+            )
+        )
     if username == "20170006" and "qazwsx".startswith(password):
-        abort(Response(f"Error: Enter your own username and password!. \n".replace("\n", '<br />')))
+        abort(
+            Response(
+                f"Error: Enter your own username and password!. \n".replace(
+                    "\n", "<br />"
+                )
+            )
+        )
 
-    path = base_dir / f'{username}.ics'
+    path = base_dir / f"{username}.ics"
     try:
         server_main(username, password, path)
     except ValidationError as _:
-        abort(Response(f"Error: Invalid password. \n"
-                       f"Please check the availability of your account and password.".replace("\n", '<br />')))
+        abort(
+            Response(
+                f"Error: Invalid password. \n"
+                f"Please check the availability of your account and password.".replace(
+                    "\n", "<br />"
+                )
+            )
+        )
     except Exception as _:
-        abort(Response((f"Error".center(93, "=") +
-                        f"\n"
-                        f"{traceback.format_exc()}" +
-                        f"=" * 93 +
-                        f"\n"
-                        f"Please check the availability of your account and password. \n"
-                        f"If this problem cannot be solved, "
-                        f"please report it at https://github.com/CQU-AI/cqu-kb/issues\n").replace("\n", '<br />')))
+        abort(
+            Response(
+                (
+                    f"Error".center(93, "=") + f"\n"
+                    f"{traceback.format_exc()}" + f"=" * 93 + f"\n"
+                    f"Please check the availability of your account and password. \n"
+                    f"If this problem cannot be solved, "
+                    f"please report it at https://github.com/CQU-AI/cqu-kb/issues\n"
+                ).replace("\n", "<br />")
+            )
+        )
 
     return send_from_directory(
         directory=base_dir.absolute(),
-        filename=f'{username}.ics',
-        mimetype='text/calendar',
+        filename=f"{username}.ics",
+        mimetype="text/calendar",
         as_attachment=True,
-        attachment_filename=f'{username}.ics'
+        attachment_filename=f"{username}.ics",
     )
 
 
-if __name__ == '__main__':
-    app.run(host='0.0.0.0', port=5000, debug=False)
+if __name__ == "__main__":
+    app.run(host="0.0.0.0", port=5000, debug=False)
diff --git a/src/cqu_kb/__init__.py b/src/cqu_kb/__init__.py
index 9f8fbb1..835f883 100644
--- a/src/cqu_kb/__init__.py
+++ b/src/cqu_kb/__init__.py
@@ -3,4 +3,4 @@
 
 __all__ = ["main", "console_main"]
 
-# check_update('cqu-kb')
+check_update("cqu-kb")
diff --git a/src/cqu_kb/__main__.py b/src/cqu_kb/__main__.py
index ca64126..35e69ba 100644
--- a/src/cqu_kb/__main__.py
+++ b/src/cqu_kb/__main__.py
@@ -1,10 +1,18 @@
 import sys
 
 from cqu_kb.config.config import config, Config
-from cqu_kb.utils import check_user, log, check_output_path
+from cqu_kb.utils import check_user, log, check_output_path, select_core
 from cqu_kb.version import __version__
-from cqu_kb.core import get_cal, get_payload
-from cqu_jxgl import Student
+
+
+def main(username, password, path):
+    core = select_core(username)
+    cal = core(username, password).main()
+
+    with open(path, "wb") as f:
+        f.write(cal.to_ical())
+
+    log(f"课表已经保存到{path}")
 
 
 def server_main(username, password, path):
@@ -17,28 +25,6 @@ def local_main():
     main(username, password, config["output"]["path"])
 
 
-def main(username, password, path):
-    student = Student(
-        username=username,
-        password=password
-    )
-
-    student.login()
-
-    cal = get_cal(
-        student.post(
-            url="/znpk/Pri_StuSel_rpt.aspx",
-            headers={"Content-Type": "application/x-www-form-urlencoded;charset=utf-8"},
-            data=get_payload(student)
-        ).content
-    )
-
-    with open(path, 'wb') as f:
-        f.write(cal.to_ical())
-
-    log(f'课表已经保存到{path}')
-
-
 def console_main():
     import argparse
 
@@ -47,7 +33,10 @@ def parse_args() -> argparse.Namespace:
 
         :return: Namespace with parsed arguments.
         """
-        parser = argparse.ArgumentParser(prog="kb", description="第三方 重庆大学 课表导出工具", )
+        parser = argparse.ArgumentParser(
+            prog="kb",
+            description="第三方 重庆大学 课表导出工具",
+        )
 
         parser.add_argument(
             "-v",
@@ -63,7 +52,10 @@ def parse_args() -> argparse.Namespace:
             action="store_true",
         )
         parser.add_argument(
-            "-r", "--reset", help="重置配置项", action="store_true",
+            "-r",
+            "--reset",
+            help="重置配置项",
+            action="store_true",
         )
         parser.add_argument(
             "-u",
@@ -84,7 +76,7 @@ def parse_args() -> argparse.Namespace:
             "--output",
             help="课表输出路径",
             type=str,
-            default=config['output']['path'],
+            default=config["output"]["path"],
         )
         return parser.parse_args()
 
@@ -101,5 +93,5 @@ def parse_args() -> argparse.Namespace:
     local_main()
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     local_main()
diff --git a/src/cqu_kb/core.py b/src/cqu_kb/core.py
deleted file mode 100644
index df5e927..0000000
--- a/src/cqu_kb/core.py
+++ /dev/null
@@ -1,143 +0,0 @@
-import uuid
-from datetime import datetime, timedelta
-from urllib import parse
-
-import pytz
-from bs4 import BeautifulSoup as BS
-from icalendar import Calendar, Event
-from icalendar import Timezone, vDDDTypes
-
-from cqu_kb.config import config
-
-
-def get_payload(student):
-    """
-    This function prepares the payload to be sent in HTTP POST method. There are three main fields in the payload. The
-    only thing that should be paid attention to is "Sel_XNXQ" field, which denotes the years（学年） and terms（学期）.
-
-    :param student: an instance of Student from cqu-jxgl
-    :return: payload to be used in HTTP POST
-    """
-    # First Get. Won't get any information but a cookie.
-    response = student.get("/znpk/Pri_StuSel.aspx")
-    soup = BS(response.content, features="html.parser")
-    return parse.urlencode({
-        "Sel_XNXQ": soup.find("option")['value'],
-        "rad": "on",
-        "px": "1",
-    })
-
-
-def _add_datetime(component, name, time):
-    vdatetime = vDDDTypes(time)
-    if 'VALUE' in vdatetime.params and 'TZID' in vdatetime.params:
-        vdatetime.params.pop('VALUE')
-    component.add(name, vdatetime)
-
-def get_cal(page_content):
-    soup = BS(page_content.decode('gbk'), features="html.parser")
-    tables = soup.find_all(class_="page_table")
-
-    courses_info = []
-    for i in range(len(tables) // 2):
-        table = tables[i * 2 + 1]
-        rows = table.find('tbody').find_all('tr')
-        cols_num = len(rows[0].find_all('td'))
-        for row in rows:
-            course_info = {}
-            cols = row.find_all('td')
-            course_info.update({'course_name': cols[1].text.split(']')[-1] + ("" if cols_num == 13 else "（实验）")})
-            course_info.update({'teacher': cols[
-                -4 if cols_num == 13 else -5
-            ].text})
-            course_info.update({'weeks': cols[-3].text})
-            course_info.update({'time': cols[-2].text.replace('节]', '')})
-            course_info.update({'location': cols[-1].text})
-            courses_info.append(course_info)
-    for i in range(len(courses_info)):
-        if courses_info[i]['course_name'] == '' or courses_info[i]['course_name'] == '（实验）':
-            courses_info[i]['course_name'] = courses_info[i - 1]['course_name']
-
-    chinese_to_numbers = {
-        '一': 0,
-        '二': 1,
-        '三': 2,
-        '四': 3,
-        '五': 4,
-        '六': 5,
-        '日': 6
-    }
-
-    coursenum_to_time = {
-        '1': (timedelta(hours=8, minutes=30), timedelta(hours=9, minutes=15)),
-        '2': (timedelta(hours=9, minutes=25), timedelta(hours=10, minutes=10)),
-        '3': (timedelta(hours=10, minutes=30), timedelta(hours=11, minutes=15)),
-        '4': (timedelta(hours=11, minutes=25), timedelta(hours=12, minutes=10)),
-        '5': (timedelta(hours=13, minutes=30), timedelta(hours=14, minutes=15)),
-        '6': (timedelta(hours=14, minutes=25), timedelta(hours=15, minutes=10)),
-        '7': (timedelta(hours=15, minutes=20), timedelta(hours=16, minutes=5)),
-        '8': (timedelta(hours=16, minutes=25), timedelta(hours=17, minutes=10)),
-        '9': (timedelta(hours=17, minutes=20), timedelta(hours=18, minutes=5)),
-        '10': (timedelta(hours=19, minutes=0), timedelta(hours=19, minutes=45)),
-        '11': (timedelta(hours=19, minutes=55), timedelta(hours=20, minutes=40)),
-        '12': (timedelta(hours=20, minutes=50), timedelta(hours=21, minutes=35)),
-        '13': (timedelta(hours=21, minutes=45), timedelta(hours=22, minutes=30)),
-    }
-
-    term_start_time = datetime(
-        year=int(config["term_start_time"]["year"]),
-        month=int(config["term_start_time"]["month"]),
-        day=int(config["term_start_time"]["day"]),
-        tzinfo=pytz.timezone('Asia/Shanghai')
-    )
-
-    events = []
-
-    for course in courses_info:
-        week_nums = []
-        week_segs = course['weeks'].split(',')
-        for seg in week_segs:
-            delimiter = [int(i) for i in seg.split('-')]
-            start = delimiter[0]
-            end = delimiter[1] if len(delimiter) == 2 else start
-            for i in range(start, end + 1):
-                week_nums.append(i)
-        day = chinese_to_numbers[course['time'].split('[')[0]]
-        seg = course['time'].split('[')[1].split('-')
-        if len(seg) == 2:
-            inweek_delta_start = timedelta(days=day) + coursenum_to_time[seg[0]][0]
-            inweek_delta_end = timedelta(days=day) + coursenum_to_time[seg[1]][1]
-            for week_num in week_nums:
-                event_start_datetime = term_start_time + (week_num - 1) * timedelta(days=7) + inweek_delta_start
-                event_end_datetime = term_start_time + (week_num - 1) * timedelta(days=7) + inweek_delta_end
-                event = Event()
-                event.add('summary', '[{}]{}'.format(course['teacher'], course['course_name']))
-                event.add('location', course['location'])
-                _add_datetime(event, 'dtstart', event_start_datetime)
-                _add_datetime(event, 'dtend', event_end_datetime)
-                # Fix #2: 添加 dtstamp 与 uid 属性
-                event.add('dtstamp', datetime.utcnow())
-                namespace = uuid.UUID(
-                    bytes=int(event_start_datetime.timestamp()).to_bytes(length=8, byteorder='big') +
-                          int(event_end_datetime.timestamp()).to_bytes(length=8, byteorder='big')
-                )
-                event.add('uid', uuid.uuid3(namespace, f"{course['course_name']}-{course['teacher']}"))
-
-                events.append(event)
-
-    cal = Calendar()
-    cal.add('prodid', f'-//重庆大学课表//{config["user_info"]["username"]}//Powered By cqu-kb//')
-    cal.add('version', '2.0')
-    cal.add_component(Timezone.from_ical("BEGIN:VTIMEZONE\n"
-                                         "TZID:Asia/Shanghai\n"
-                                         "X-LIC-LOCATION:Asia/Shanghai\n"
-                                         "BEGIN:STANDARD\n"
-                                         "TZNAME:CST\n"
-                                         "DTSTART:16010101T000000\n"
-                                         "TZOFFSETFROM:+0800\n"
-                                         "TZOFFSETTO:+0800\n"
-                                         "END:STANDARD\n"
-                                         "END:VTIMEZONE\n"))
-    for event in events:
-        cal.add_component(event)
-    return cal
diff --git a/src/cqu_kb/core/KBCore.py b/src/cqu_kb/core/KBCore.py
new file mode 100644
index 0000000..0031885
--- /dev/null
+++ b/src/cqu_kb/core/KBCore.py
@@ -0,0 +1,141 @@
+import uuid
+from abc import abstractmethod, ABC
+from datetime import datetime, timedelta
+
+import pytz
+from icalendar import Calendar, Event
+from icalendar import Timezone, vDDDTypes
+
+from cqu_kb.config import config
+
+
+class KBCore(ABC):
+    def __init__(self, username, password):
+        self.password = password
+        self.username = username
+
+    @abstractmethod
+    def _get_payload(self, **kwargs):
+        pass
+
+    @abstractmethod
+    def main(self):
+        pass
+
+    @abstractmethod
+    def get_course_info(self, page_content):
+        pass
+
+    @staticmethod
+    def _add_datetime(component, name, time):
+        vdatetime = vDDDTypes(time)
+        if "VALUE" in vdatetime.params and "TZID" in vdatetime.params:
+            vdatetime.params.pop("VALUE")
+        component.add(name, vdatetime)
+
+    def get_cal(self, course_info):
+        chinese_to_numbers = {"一": 0, "二": 1, "三": 2, "四": 3, "五": 4, "六": 5, "日": 6}
+
+        coursenum_to_time = {
+            "1": (timedelta(hours=8, minutes=30), timedelta(hours=9, minutes=15)),
+            "2": (timedelta(hours=9, minutes=25), timedelta(hours=10, minutes=10)),
+            "3": (timedelta(hours=10, minutes=30), timedelta(hours=11, minutes=15)),
+            "4": (timedelta(hours=11, minutes=25), timedelta(hours=12, minutes=10)),
+            "5": (timedelta(hours=13, minutes=30), timedelta(hours=14, minutes=15)),
+            "6": (timedelta(hours=14, minutes=25), timedelta(hours=15, minutes=10)),
+            "7": (timedelta(hours=15, minutes=20), timedelta(hours=16, minutes=5)),
+            "8": (timedelta(hours=16, minutes=25), timedelta(hours=17, minutes=10)),
+            "9": (timedelta(hours=17, minutes=20), timedelta(hours=18, minutes=5)),
+            "10": (timedelta(hours=19, minutes=0), timedelta(hours=19, minutes=45)),
+            "11": (timedelta(hours=19, minutes=55), timedelta(hours=20, minutes=40)),
+            "12": (timedelta(hours=20, minutes=50), timedelta(hours=21, minutes=35)),
+            "13": (timedelta(hours=21, minutes=45), timedelta(hours=22, minutes=30)),
+        }
+
+        term_start_time = datetime(
+            year=int(config["term_start_time"]["year"]),
+            month=int(config["term_start_time"]["month"]),
+            day=int(config["term_start_time"]["day"]),
+            tzinfo=pytz.timezone("Asia/Shanghai"),
+        )
+
+        events = []
+
+        for course in course_info:
+            week_nums = []
+            week_segs = course["weeks"].split(",")
+            for seg in week_segs:
+                delimiter = [int(i) for i in seg.split("-")]
+                start = delimiter[0]
+                end = delimiter[1] if len(delimiter) == 2 else start
+                for i in range(start, end + 1):
+                    week_nums.append(i)
+            if not course["time"].split("[")[0].isdigit():
+                day = chinese_to_numbers[course["time"].split("[")[0]]
+            else:
+                day = int(course["time"].split("[")[0])
+            seg = course["time"].split("[")[1].split("-")
+            if len(seg) == 2:
+                inweek_delta_start = timedelta(days=day) + coursenum_to_time[seg[0]][0]
+                inweek_delta_end = timedelta(days=day) + coursenum_to_time[seg[1]][1]
+                for week_num in week_nums:
+                    event_start_datetime = (
+                        term_start_time
+                        + (week_num - 1) * timedelta(days=7)
+                        + inweek_delta_start
+                    )
+                    event_end_datetime = (
+                        term_start_time
+                        + (week_num - 1) * timedelta(days=7)
+                        + inweek_delta_end
+                    )
+                    event = Event()
+                    event.add(
+                        "summary",
+                        "[{}]{}".format(course["teacher"], course["course_name"]),
+                    )
+                    event.add("location", course["location"])
+                    self._add_datetime(event, "dtstart", event_start_datetime)
+                    self._add_datetime(event, "dtend", event_end_datetime)
+                    # Fix #2: 添加 dtstamp 与 uid 属性
+                    event.add("dtstamp", datetime.utcnow())
+                    namespace = uuid.UUID(
+                        bytes=int(event_start_datetime.timestamp()).to_bytes(
+                            length=8, byteorder="big"
+                        )
+                        + int(event_end_datetime.timestamp()).to_bytes(
+                            length=8, byteorder="big"
+                        )
+                    )
+                    event.add(
+                        "uid",
+                        uuid.uuid3(
+                            namespace, f"{course['course_name']}-{course['teacher']}"
+                        ),
+                    )
+
+                    events.append(event)
+
+        cal = Calendar()
+        cal.add(
+            "prodid",
+            f'-//重庆大学课表//{config["user_info"]["username"]}//Powered By cqu-kb//',
+        )
+        cal.add("version", "2.0")
+        cal.add_component(
+            Timezone.from_ical(
+                "BEGIN:VTIMEZONE\n"
+                "TZID:Asia/Shanghai\n"
+                "X-LIC-LOCATION:Asia/Shanghai\n"
+                "BEGIN:STANDARD\n"
+                "TZNAME:CST\n"
+                "DTSTART:16010101T000000\n"
+                "TZOFFSETFROM:+0800\n"
+                "TZOFFSETTO:+0800\n"
+                "END:STANDARD\n"
+                "END:VTIMEZONE\n"
+            )
+        )
+        for event in events:
+            cal.add_component(event)
+        return cal
diff --git a/src/cqu_kb/core/KBCoreGrad.py b/src/cqu_kb/core/KBCoreGrad.py
new file mode 100644
index 0000000..dc97511
--- /dev/null
+++ b/src/cqu_kb/core/KBCoreGrad.py
@@ -0,0 +1,65 @@
+import re
+
+from bs4 import BeautifulSoup as BS
+from requests import Session
+
+from cqu_kb.core.KBCore import KBCore
+
+
+class KBCoreGrad(KBCore):
+    def _get_payload(self):
+        return {
+            "userId": self.username,
+            "password": self.password,
+            "userType": "student",
+            "imageField.x": "50",
+            "imageField.y": "6",
+        }
+
+    def main(self):
+        # 实例化 requests.Session 对象
+        s = Session()
+
+        # url 配置
+        base_url = "http://mis.cqu.edu.cn/mis"
+        login_url = base_url + "/login.jsp"
+        select_course_url = base_url + "/student/plan/select_course.jsp"
+        cal_base_url = base_url + "/curricula/show_stu.jsp?stuSerial="
+
+        # 系统登录
+        s.post(login_url, self._get_payload())
+
+        # 获取 stuSerial 参数
+        res = s.get(select_course_url)
+        stu_serial = re.findall(r"stuSerial=(\d*)?", res.text)[0]
+
+        # 获取课表 html
+        cal_url = cal_base_url + stu_serial
+        cal = s.get(cal_url)
+
+        course_info = self.get_course_info(cal.text)
+        return self.get_cal(course_info)
+
+    def get_course_info(self, page_content):
+        page_content = page_content.replace("<br/>", "[br]").replace("<br>", "[br]")
+
+        soup = BS(page_content, features="html.parser")
+        table = soup.find_all("table")[0]
+
+        courses_info = []
+        for line in table.find_all("tr")[2:]:
+            for i, element in enumerate(line.find_all("td")[1:-1]):
+                courses = tuple(filter(lambda x: x != "", element.text.split("[br]")))
+                for j in range(len(courses) // 7):
+                    courses_info.append(
+                        {
+                            "course_name": courses[j * 7 + 2][3:],
+                            "teacher": courses[j * 7 + 5][3:],
+                            "weeks": courses[j * 7 + 3][3:-1].replace(" ", ","),
+                            "time": "{}[{}".format(
+                                i, courses[j * 7 + 4][3:]
+                            ),  # compromise with UnderGrad core
+                            "location": courses[j * 7 + 6][3:],
+                        }
+                    )
+        return courses_info
diff --git a/src/cqu_kb/core/KBCoreUnderGrad.py b/src/cqu_kb/core/KBCoreUnderGrad.py
new file mode 100644
index 0000000..d0d4511
--- /dev/null
+++ b/src/cqu_kb/core/KBCoreUnderGrad.py
@@ -0,0 +1,70 @@
+from urllib import parse
+
+from bs4 import BeautifulSoup as BS
+from cqu_jxgl import Student
+
+from cqu_kb.core.KBCore import KBCore
+
+
+class KBCoreUnderGrad(KBCore):
+    def _get_payload(self, student):
+        """
+        This function prepares the payload to be sent in HTTP POST method. There are three main fields in the payload. The
+        only thing that should be paid attention to is "Sel_XNXQ" field, which denotes the years（学年） and terms（学期）.
+
+        :param student: an instance of Student from cqu-jxgl
+        :return: payload to be used in HTTP POST
+        """
+        # First Get. Won't get any information but a cookie.
+        response = student.get("/znpk/Pri_StuSel.aspx")
+        soup = BS(response.content, features="html.parser")
+        return parse.urlencode(
+            {
+                "Sel_XNXQ": soup.find("option")["value"],
+                "rad": "on",
+                "px": "1",
+            }
+        )
+
+    def main(self):
+        student = Student(username=self.username, password=self.password)
+
+        student.login()
+        page_content = student.post(
+            url="/znpk/Pri_StuSel_rpt.aspx",
+            headers={"Content-Type": "application/x-www-form-urlencoded;charset=utf-8"},
+            data=self._get_payload(student),
+        ).content
+        course_info = self.get_course_info(page_content)
+        return self.get_cal(course_info)
+
+    def get_course_info(self, page_content):
+        soup = BS(page_content.decode("gbk"), features="html.parser")
+        tables = soup.find_all(class_="page_table")
+
+        courses_info = []
+        for i in range(len(tables) // 2):
+            table = tables[i * 2 + 1]
+            rows = table.find("tbody").find_all("tr")
+            cols_num = len(rows[0].find_all("td"))
+            for row in rows:
+                course_info = {}
+                cols = row.find_all("td")
+                course_info.update(
+                    {
+                        "course_name": cols[1].text.split("]")[-1]
+                        + ("" if cols_num == 13 else "（实验）")
+                    }
+                )
+                course_info.update({"teacher": cols[-4 if cols_num == 13 else -5].text})
+                course_info.update({"weeks": cols[-3].text})
+                course_info.update({"time": cols[-2].text.replace("节]", "")})
+                course_info.update({"location": cols[-1].text})
+                courses_info.append(course_info)
+        for i in range(len(courses_info)):
+            if (
+                courses_info[i]["course_name"] == ""
+                or courses_info[i]["course_name"] == "（实验）"
+            ):
+                courses_info[i]["course_name"] = courses_info[i - 1]["course_name"]
+        return courses_info
diff --git a/src/cqu_kb/core/__init__.py b/src/cqu_kb/core/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/src/cqu_kb/utils.py b/src/cqu_kb/utils.py
index c45f781..e47ccde 100644
--- a/src/cqu_kb/utils.py
+++ b/src/cqu_kb/utils.py
@@ -8,22 +8,24 @@
 import requests
 
 from cqu_kb.config.config import config
+from cqu_kb.core.KBCoreGrad import KBCoreGrad
+from cqu_kb.core.KBCoreUnderGrad import KBCoreUnderGrad
 from cqu_kb.version import __version__
 
 ERROR_COUNT = 0
 
 
 def check_output_path():
-    if config['output']['path'] is None:
+    if config["output"]["path"] is None:
         flag = False
         for i in ["Desktop", "桌面", "desktop"]:
             if (Path.home() / i).is_dir():
                 flag = True
                 break
         if flag:
-            config['output']['path'] = Path.home() / i / "课表.ics"
+            config["output"]["path"] = Path.home() / i / "课表.ics"
         else:
-            config['output']['path'] = Path("./课表.ics").absolute()
+            config["output"]["path"] = Path("./课表.ics").absolute()
 
 
 def exit():
@@ -53,8 +55,8 @@ def reset_error_count():
 
 def check_user():
     if (
-            config["user_info"]["username"] is None
-            or config["user_info"]["password"] is None
+        config["user_info"]["username"] is None
+        or config["user_info"]["password"] is None
     ):
         print("未找到有效的帐号和密码，请输入你的帐号和密码，它们将被保存在你的电脑上以备下次使用")
         try:
@@ -77,3 +79,20 @@ def check_update(project_name):
             f"{project_name}的最新版本为{latest_version}，当前安装的是{__version__}，建议使用`pip install {project_name} -U`来升级",
             warning=True,
         )
+
+
+def select_core(username):
+    if is_under_grad(username):
+        return KBCoreUnderGrad
+    elif is_grad(username):
+        return KBCoreGrad
+    else:
+        raise AttributeError(f"无法匹配的学号：{username}")
+
+
+def is_under_grad(username):
+    return username.isdigit() and len(username) == 8 and username.startswith("20")
+
+
+def is_grad(username):
+    return username.isdigit() and len(username) == 12 and username.startswith("20")
diff --git a/src/cqu_kb/version.py b/src/cqu_kb/version.py
index 52c1159..de0f3eb 100644
--- a/src/cqu_kb/version.py
+++ b/src/cqu_kb/version.py
@@ -1,2 +1,2 @@
 """This file is auto-generated by setup.py, please do not alter."""
-__version__ = "0.2.2"
+__version__ = "0.3.0"