diff --git "a/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/1.Git\347\256\200\344\273\213/config.json" "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/1.Git\347\256\200\344\273\213/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..294b736dad9057e58df2d224365c21721df9119d
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/1.Git\347\256\200\344\273\213/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-62c30f9c31f64a1d96af732c47c93f04",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/2.Git\345\256\211\350\243\205/config.json" "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/2.Git\345\256\211\350\243\205/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..0fc69c4b905f156579ed2e8a8cc09dd3becbf442
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/2.Git\345\256\211\350\243\205/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-17121b66f9a942629bc455f320b28910",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/3.Git\344\275\277\347\224\250/config.json" "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/3.Git\344\275\277\347\224\250/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..cf21bd10389ea68b6ac5b42e92c248e49bb6dc77
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/3.Git\344\275\277\347\224\250/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-598d225d1a78453d8992345f8f7902ba",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/4.\347\211\210\346\234\254\347\256\241\347\220\206/config.json" "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/4.\347\211\210\346\234\254\347\256\241\347\220\206/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..7d97b0f67941f783e322c11bce9f9bbe91ccf847
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/4.\347\211\210\346\234\254\347\256\241\347\220\206/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-f0d68868583b48d0851c7add33e2f8ff",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/5.\345\210\206\346\224\257\347\256\241\347\220\206/config.json" "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/5.\345\210\206\346\224\257\347\256\241\347\220\206/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..0babf8af3af3c878cd58b652204acd537a795008
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/5.\345\210\206\346\224\257\347\256\241\347\220\206/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-5b37ae204b1f4183b1a2853f32698407",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/6.Git\346\240\207\347\255\276/config.json" "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/6.Git\346\240\207\347\255\276/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..09beccba18fcadad6693c5576c0a4bc91fa3aa3a
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/6.Git\346\240\207\347\255\276/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-7b2351b6989f4ec19655498bbb4bafb1",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/config.json" "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..6c4f26403e91c6558bac17062633530d9b29c44e
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/1.Git\345\205\245\351\227\250/config.json"
@@ -0,0 +1,4 @@
+{
+  "node_id": "gml-426d7dad0f844c6d9bc1d6c4c860585c",
+  "keywords": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/1.MarkDown\344\273\213\347\273\215/config.json" "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/1.MarkDown\344\273\213\347\273\215/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..dc01f751bde8a90743807059fe0638a861c46a89
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/1.MarkDown\344\273\213\347\273\215/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-e67e64c1c880432ab6bc1b0452124ec0",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/2.\346\256\265\350\220\275\345\217\212\345\274\272\350\260\203/config.json" "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/2.\346\256\265\350\220\275\345\217\212\345\274\272\350\260\203/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..99e7b7213023be580985ea58c9d9a29e1cc95304
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/2.\346\256\265\350\220\275\345\217\212\345\274\272\350\260\203/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-627f564073834c8d86e45f126ac628df",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/3.\346\240\207\351\242\230/config.json" "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/3.\346\240\207\351\242\230/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..bf43f50c304d38a38eb6d6c821205e64cf880c7c
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/3.\346\240\207\351\242\230/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-30e9989f9a5f44fab349734a8e4479a3",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/4.\351\223\276\346\216\245/config.json" "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/4.\351\223\276\346\216\245/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..4570191eb82648b8273a90f60ea3e44b8cad1bf4
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/4.\351\223\276\346\216\245/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-3cb459e3d1a147a8b89291c1ef4147c7",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/5.\345\233\276\347\211\207/config.json" "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/5.\345\233\276\347\211\207/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..bf5d39eec7673e499d82d03aa78fe6376862e928
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/5.\345\233\276\347\211\207/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-2f1e2810b721429dba664414438b6d87",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/6.\345\210\227\350\241\250/config.json" "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/6.\345\210\227\350\241\250/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..288ef70cd6218297bbfe062ce5cf11cc283b5573
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/6.\345\210\227\350\241\250/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-b4a4f06aa5114c3fa6a590d659037370",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/7.\345\210\206\351\232\224\347\272\277\345\217\212\345\274\225\347\224\250/config.json" "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/7.\345\210\206\351\232\224\347\272\277\345\217\212\345\274\225\347\224\250/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..af4ddfb68d28ec74f1a260bba8ae9a8d9b498c68
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/7.\345\210\206\351\232\224\347\272\277\345\217\212\345\274\225\347\224\250/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-b6b6f01fb86141768c5b242327f1e0fa",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/8.\344\273\243\347\240\201\345\235\227/config.json" "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/8.\344\273\243\347\240\201\345\235\227/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..e7db5538d342f1195c89cd8daa991daf4dcf2b62
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/8.\344\273\243\347\240\201\345\235\227/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-2e87affacacd4078a3ba55a5a15a8f7a",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/9.\350\241\250\346\240\274/config.json" "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/9.\350\241\250\346\240\274/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..5e46ffd1d6cb8855a27ccd5b9222822b7e31d283
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/9.\350\241\250\346\240\274/config.json"
@@ -0,0 +1,6 @@
+{
+  "node_id": "gml-11620ba793c74faa9a5117ca07d748d6",
+  "keywords": [],
+  "children": [],
+  "export": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/config.json" "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..7b8d40d8084148f56cb3fac13c5e48c9d476e74b
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/2.MarkDown\345\205\245\351\227\250/config.json"
@@ -0,0 +1,4 @@
+{
+  "node_id": "gml-e5b1eb56008b451699a9e7e6d941c8ca",
+  "keywords": []
+}
\ No newline at end of file
diff --git "a/data/1.gml\345\210\235\351\230\266/config.json" "b/data/1.gml\345\210\235\351\230\266/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..b05d3fd39b8c7553c8034225839b0688b1c368d1
--- /dev/null
+++ "b/data/1.gml\345\210\235\351\230\266/config.json"
@@ -0,0 +1,4 @@
+{
+  "node_id": "gml-3acda6f103e94664800f91494aff4099",
+  "keywords": []
+}
\ No newline at end of file
diff --git "a/data/2.gml\344\270\255\351\230\266/config.json" "b/data/2.gml\344\270\255\351\230\266/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..a4e896712ff90017776fa1da4b033fcfb17ba131
--- /dev/null
+++ "b/data/2.gml\344\270\255\351\230\266/config.json"
@@ -0,0 +1,4 @@
+{
+  "node_id": "gml-a94f8931a29e42749c65af33b5f00ffa",
+  "keywords": []
+}
\ No newline at end of file
diff --git "a/data/3.gml\351\253\230\351\230\266/config.json" "b/data/3.gml\351\253\230\351\230\266/config.json"
new file mode 100644
index 0000000000000000000000000000000000000000..6cc25fca75326ee1192e3d98a5eae54235741be9
--- /dev/null
+++ "b/data/3.gml\351\253\230\351\230\266/config.json"
@@ -0,0 +1,4 @@
+{
+  "node_id": "gml-ec7eb3a512204261a14eafc36bc55188",
+  "keywords": []
+}
\ No newline at end of file
diff --git a/data/config.json b/data/config.json
new file mode 100644
index 0000000000000000000000000000000000000000..7dfbabe72afb28e6fd03d003ad9e79c637dbefe6
--- /dev/null
+++ b/data/config.json
@@ -0,0 +1,5 @@
+{
+  "tree_name": "gml",
+  "keywords": [],
+  "node_id": "gml-2edf9242568f4812bda2dd5913c09bd3"
+}
\ No newline at end of file
diff --git a/data/tree.json b/data/tree.json
new file mode 100644
index 0000000000000000000000000000000000000000..cf1248d0b7524e9d58785a09815845ddb9caaf67
--- /dev/null
+++ b/data/tree.json
@@ -0,0 +1,151 @@
+{
+  "gml": {
+    "node_id": "gml-2edf9242568f4812bda2dd5913c09bd3",
+    "keywords": [],
+    "children": [
+      {
+        "gml初阶": {
+          "node_id": "gml-3acda6f103e94664800f91494aff4099",
+          "keywords": [],
+          "children": [
+            {
+              "Git入门": {
+                "node_id": "gml-426d7dad0f844c6d9bc1d6c4c860585c",
+                "keywords": [],
+                "children": [
+                  {
+                    "Git简介": {
+                      "node_id": "gml-62c30f9c31f64a1d96af732c47c93f04",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "Git安装": {
+                      "node_id": "gml-17121b66f9a942629bc455f320b28910",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "Git使用": {
+                      "node_id": "gml-598d225d1a78453d8992345f8f7902ba",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "版本管理": {
+                      "node_id": "gml-f0d68868583b48d0851c7add33e2f8ff",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "分支管理": {
+                      "node_id": "gml-5b37ae204b1f4183b1a2853f32698407",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "Git标签": {
+                      "node_id": "gml-7b2351b6989f4ec19655498bbb4bafb1",
+                      "keywords": [],
+                      "children": []
+                    }
+                  }
+                ]
+              }
+            },
+            {
+              "MarkDown入门": {
+                "node_id": "gml-e5b1eb56008b451699a9e7e6d941c8ca",
+                "keywords": [],
+                "children": [
+                  {
+                    "MarkDown介绍": {
+                      "node_id": "gml-e67e64c1c880432ab6bc1b0452124ec0",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "段落及强调": {
+                      "node_id": "gml-627f564073834c8d86e45f126ac628df",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "标题": {
+                      "node_id": "gml-30e9989f9a5f44fab349734a8e4479a3",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "链接": {
+                      "node_id": "gml-3cb459e3d1a147a8b89291c1ef4147c7",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "图片": {
+                      "node_id": "gml-2f1e2810b721429dba664414438b6d87",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "列表": {
+                      "node_id": "gml-b4a4f06aa5114c3fa6a590d659037370",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "分隔线及引用": {
+                      "node_id": "gml-b6b6f01fb86141768c5b242327f1e0fa",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "代码块": {
+                      "node_id": "gml-2e87affacacd4078a3ba55a5a15a8f7a",
+                      "keywords": [],
+                      "children": []
+                    }
+                  },
+                  {
+                    "表格": {
+                      "node_id": "gml-11620ba793c74faa9a5117ca07d748d6",
+                      "keywords": [],
+                      "children": []
+                    }
+                  }
+                ]
+              }
+            }
+          ]
+        }
+      },
+      {
+        "gml中阶": {
+          "node_id": "gml-a94f8931a29e42749c65af33b5f00ffa",
+          "keywords": [],
+          "children": []
+        }
+      },
+      {
+        "gml高阶": {
+          "node_id": "gml-ec7eb3a512204261a14eafc36bc55188",
+          "keywords": [],
+          "children": []
+        }
+      }
+    ]
+  }
+}
\ No newline at end of file
diff --git a/main.py b/main.py
new file mode 100644
index 0000000000000000000000000000000000000000..d9c6c020a3da13787cbfe8c73f8d09790bea0871
--- /dev/null
+++ b/main.py
@@ -0,0 +1,5 @@
+from src.tree import TreeWalker
+
+if __name__ == '__main__':
+    walker = TreeWalker("data", "gml", "Git,MarkDown,Linux 入门")
+    walker.walk()
diff --git a/src/__pycache__/tree.cpython-38.pyc b/src/__pycache__/tree.cpython-38.pyc
new file mode 100644
index 0000000000000000000000000000000000000000..f769f2142b67da7ac1a425a8aa8400139b37cf3e
Binary files /dev/null and b/src/__pycache__/tree.cpython-38.pyc differ
diff --git a/src/tree.py b/src/tree.py
new file mode 100644
index 0000000000000000000000000000000000000000..f6fb31a332e770902c7a5a590cdad446edf9e960
--- /dev/null
+++ b/src/tree.py
@@ -0,0 +1,310 @@
+import json
+import logging
+import os
+import re
+import sys
+import uuid
+
+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') 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="utf8") 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 + 1}.{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 sort_dir_list(self, dirs):
+        result = [self.extract_node_env(dir) for dir in dirs]
+        result.sort(key=lambda item: item[0])
+        return result
+
+    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, result, exist_ok=True, override=True)
+        return config
+
+    def ensure_node_id(self, config):
+        flag = False
+        if "node_id" not in config or \
+                not config["node_id"].startswith(f"{self.name}-") or \
+                config["node_id"] in id_set:
+            new_id = self.gen_node_id()
+            id_set.add(new_id)
+            config["node_id"] = new_id
+            flag = True
+
+        for child in config.get("children", []):
+            child_node = list(child.values())[0]
+            f, _ = self.ensure_node_id(child_node)
+            flag = flag or f
+
+        return flag, 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)
+            raise error
+
+    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, True, True)