diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000000000000000000000000000000000000..5ba74c7624a29abd67a2feb4e2a6a9deb1e95549
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,7 @@
+.vscode
+.idea
+.DS_Store
+__pycache__
+*.pyc
+*.zip
+*.out
\ No newline at end of file
diff --git a/main.py b/main.py
new file mode 100644
index 0000000000000000000000000000000000000000..dc93161655eb0d55fe82f3542909a26dd0240417
--- /dev/null
+++ b/main.py
@@ -0,0 +1,6 @@
+# -*- coding: utf-8 -*-
+from src.tree import TreeWalker
+
+if __name__ == '__main__':
+    walker = TreeWalker("data", "dailycode", "dailycode")
+    walker.walk()
diff --git a/src/tree.py b/src/tree.py
new file mode 100644
index 0000000000000000000000000000000000000000..95e1cbc5812810e30465eccc2632464caa5438e7
--- /dev/null
+++ b/src/tree.py
@@ -0,0 +1,296 @@
+# -*- coding: utf-8 -*-
+import logging
+from genericpath import exists
+import json
+import os
+import uuid
+import sys
+import re
+
+id_set = set()
+logger = logging.getLogger(__name__)
+logger.setLevel(logging.INFO)
+handler = logging.StreamHandler(sys.stdout)
+formatter = logging.Formatter('%(asctime)s - %(levelname)s - %(message)s')
+handler.setFormatter(formatter)
+logger.addHandler(handler)
+
+
+def load_json(p):
+    with open(p, 'r', encoding='utf-8') as f:
+        return json.loads(f.read())
+
+
+def dump_json(p, j, exist_ok=False, override=False):
+    if os.path.exists(p):
+        if exist_ok:
+            if not override:
+                return
+        else:
+            logger.error(f"{p} already exist")
+            sys.exit(0)
+
+    with open(p, 'w+', encoding='utf-8') as f:
+        f.write(json.dumps(j, indent=2, ensure_ascii=False))
+
+
+def ensure_config(path):
+    config_path = os.path.join(path, "config.json")
+    if not os.path.exists(config_path):
+        node = {"keywords": []}
+        dump_json(config_path, node, exist_ok=True, override=False)
+        return node
+    else:
+        return load_json(config_path)
+
+
+def parse_no_name(d):
+    p = r'(\d+)\.(.*)'
+    m = re.search(p, d)
+
+    try:
+        no = int(m.group(1))
+        dir_name = m.group(2)
+    except:
+        sys.exit(0)
+
+    return no, dir_name
+
+
+def check_export(base, cfg):
+    flag = False
+    exports = []
+    for export in cfg.get('export', []):
+        ecfg_path = os.path.join(base, export)
+        if os.path.exists(ecfg_path):
+            exports.append(export)
+        else:
+            flag = True
+    if flag:
+        cfg["export"] = exports
+    return flag
+
+
+class TreeWalker:
+    def __init__(self, root, tree_name, title=None, log=None):
+        self.name = tree_name
+        self.root = root
+        self.title = tree_name if title is None else title
+        self.tree = {}
+        self.logger = logger if log is None else log
+
+    def walk(self):
+        root = self.load_root()
+        root_node = {
+            "node_id": root["node_id"],
+            "keywords": root["keywords"],
+            "children": []
+        }
+        self.tree[root["tree_name"]] = root_node
+        self.load_levels(root_node)
+        self.load_chapters(self.root, root_node)
+        for index, level in enumerate(root_node["children"]):
+            level_title = list(level.keys())[0]
+            level_node = list(level.values())[0]
+            level_path = os.path.join(self.root, f"{index+1}.{level_title}")
+            self.load_chapters(level_path, level_node)
+            for index, chapter in enumerate(level_node["children"]):
+                chapter_title = list(chapter.keys())[0]
+                chapter_node = list(chapter.values())[0]
+                chapter_path = os.path.join(
+                    level_path, f"{index+1}.{chapter_title}")
+                self.load_sections(chapter_path, chapter_node)
+                for index, section_node in enumerate(chapter_node["children"]):
+                    section_title = list(section_node.keys())[0]
+                    full_path = os.path.join(
+                        chapter_path, f"{index}.{section_title}")
+                    if os.path.isdir(full_path):
+                        self.ensure_exercises(full_path)
+
+        tree_path = os.path.join(self.root, "tree.json")
+        dump_json(tree_path, self.tree, exist_ok=True, override=True)
+        return self.tree
+
+    def load_levels(self, root_node):
+        levels = []
+        for level in os.listdir(self.root):
+            if not os.path.isdir(level):
+                continue
+            level_path = os.path.join(self.root, level)
+            num, config = self.load_level_node(level_path)
+            levels.append((num, config))
+
+        levels = self.resort_children(self.root, levels)
+        root_node["children"] = [item[1] for item in levels]
+        return root_node
+
+    def load_level_node(self, level_path):
+        config = self.ensure_level_config(level_path)
+        num, name = self.extract_node_env(level_path)
+
+        result = {
+            name: {
+                "node_id": config["node_id"],
+                "keywords": config["keywords"],
+                "children": [],
+            }
+        }
+
+        return num, result
+
+    def load_chapters(self, base, level_node):
+        chapters = []
+        for name in os.listdir(base):
+            full_name = os.path.join(base, name)
+            if os.path.isdir(full_name):
+                num, chapter = self.load_chapter_node(full_name)
+                chapters.append((num, chapter))
+
+        chapters = self.resort_children(base, chapters)
+        level_node["children"] = [item[1] for item in chapters]
+        return level_node
+
+    def load_sections(self, base, chapter_node):
+        sections = []
+        for name in os.listdir(base):
+            full_name = os.path.join(base, name)
+            if os.path.isdir(full_name):
+                num, section = self.load_section_node(full_name)
+                sections.append((num, section))
+
+        sections = self.resort_children(base, sections)
+        chapter_node["children"] = [item[1] for item in sections]
+        return chapter_node
+
+    def resort_children(self, base, children):
+        children.sort(key=lambda item: item[0])
+        for index, [number, element] in enumerate(children):
+            title = list(element.keys())[0]
+            origin = os.path.join(base, f"{number}.{title}")
+            posted = os.path.join(base, f"{index+1}.{title}")
+            if origin != posted:
+                self.logger.info(f"rename [{origin}] to [{posted}]")
+            os.rename(origin, posted)
+        return children
+
+    def ensure_chapters(self):
+        for subdir in os.listdir(self.root):
+            self.ensure_level_config(subdir)
+
+    def load_root(self):
+        config_path = os.path.join(self.root, "config.json")
+        if not os.path.exists(config_path):
+            config = {
+                "tree_name": self.name,
+                "keywords": [],
+                "node_id": self.gen_node_id(),
+            }
+            dump_json(config_path, config, exist_ok=True, override=True)
+        else:
+            config = load_json(config_path)
+            flag, result = self.ensure_node_id(config)
+            if flag:
+                dump_json(config_path, result, exist_ok=True, override=True)
+
+        return config
+
+    def ensure_level_config(self, path):
+        config_path = os.path.join(path, "config.json")
+        if not os.path.exists(config_path):
+            config = {
+                "node_id": self.gen_node_id()
+            }
+            dump_json(config_path, config, exist_ok=True, override=True)
+        else:
+            config = load_json(config_path)
+            flag, result = self.ensure_node_id(config)
+            if flag:
+                dump_json(config_path, config, exist_ok=True, override=True)
+        return config
+
+    def ensure_chapter_config(self, path):
+        config_path = os.path.join(path, "config.json")
+        if not os.path.exists(config_path):
+            config = {
+                "node_id": self.gen_node_id(),
+                "keywords": []
+            }
+            dump_json(config_path, config, exist_ok=True, override=True)
+        else:
+            config = load_json(config_path)
+            flag, result = self.ensure_node_id(config)
+            if flag:
+                dump_json(config_path, config, exist_ok=True, override=True)
+        return config
+
+    def ensure_section_config(self, path):
+        config_path = os.path.join(path, "config.json")
+        if not os.path.exists(config_path):
+            config = {
+                "node_id": self.gen_node_id(),
+                "keywords": [],
+                "children": [],
+                "export": []
+            }
+            dump_json(config_path, config, exist_ok=True, override=True)
+        else:
+            config = load_json(config_path)
+            flag, result = self.ensure_node_id(config)
+            if flag:
+                dump_json(config_path, config, exist_ok=True, override=True)
+        return config
+
+    def ensure_node_id(self, config):
+        if "node_id" not in config:
+            config["node_id"] = self.gen_node_id()
+            return True, config
+        else:
+            return False, config
+
+    def gen_node_id(self):
+        return f"{self.name}-{uuid.uuid4().hex}"
+
+    def extract_node_env(self, path):
+        try:
+            _, dir = os.path.split(path)
+            self.logger.info(path)
+            number, title = dir.split(".", 1)
+            return int(number), title
+        except Exception as error:
+            self.logger.error(f"目录 [{path}] 解析失败，结构不合法，可能是缺少序号")
+            sys.exit(1)
+
+    def load_chapter_node(self, full_name):
+        config = self.ensure_chapter_config(full_name)
+        num, name = self.extract_node_env(full_name)
+        result = {
+            name: {
+                "node_id": config["node_id"],
+                "keywords": config["keywords"],
+                "children": [],
+            }
+        }
+        return num, result
+
+    def load_section_node(self, full_name):
+        config = self.ensure_section_config(full_name)
+        num, name = self.extract_node_env(full_name)
+        result = {
+            name: {
+                "node_id": config["node_id"],
+                "keywords": config["keywords"],
+                "children": config.get("children", [])
+            }
+        }
+        # if "children" in config:
+        #     result["children"] = config["children"]
+        return num, result
+
+    def ensure_exercises(self, section_path):
+        config = self.ensure_section_config(section_path)
+        for e in config.get("export", []):
+            full_name = os.path.join(section_path, e)
+            exercise = load_json(full_name)
+            if "exercise_id" not in exercise:
+                exercise["exercise_id"] = uuid.uuid4().hex
+                dump_json(full_name, exercise)