diff --git a/q3/q3_3_质量自评.md b/q3/q3_3_质量自评.md
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/q3/q3_3_质量自评.md
@@ -0,0 +1 @@
+
diff --git a/q4/q4_1/movies.json b/q4/q4_1/movies.json
new file mode 100644
index 0000000..20ba5dc
--- /dev/null
+++ b/q4/q4_1/movies.json
@@ -0,0 +1,105 @@
+{
+  "ID": "B-20260625-3464",
+  "movies": [
+    {
+      "id": 1,
+      "title": "霸王别姬",
+      "director": "Frank Darabont",
+      "year": 2004,
+      "rating": 6.8,
+      "duration": 179,
+      "genre": "科幻",
+      "actors_count": 3
+    },
+    {
+      "id": 2,
+      "title": "放牛班的春天",
+      "director": "陈凯歌",
+      "year": 2019,
+      "rating": 6.7,
+      "duration": 117,
+      "genre": "喜剧",
+      "actors_count": 5
+    },
+    {
+      "id": 3,
+      "title": "泰坦尼克号",
+      "director": "Robert Zemeckis",
+      "year": 2015,
+      "rating": 9.1,
+      "duration": 177,
+      "genre": "爱情",
+      "actors_count": 4
+    },
+    {
+      "id": 4,
+      "title": "三傻大闹宝莱坞",
+      "director": "James Cameron",
+      "year": 2024,
+      "rating": 7.6,
+      "duration": 117,
+      "genre": "冒险",
+      "actors_count": 5
+    },
+    {
+      "id": 5,
+      "title": "阿甘正传",
+      "director": "宫崎骏",
+      "year": 2016,
+      "rating": 8.0,
+      "duration": 146,
+      "genre": "喜剧",
+      "actors_count": 3
+    },
+    {
+      "id": 6,
+      "title": "星际穿越",
+      "director": "Christopher Nolan",
+      "year": 2010,
+      "rating": 9.2,
+      "duration": 168,
+      "genre": "爱情",
+      "actors_count": 2
+    },
+    {
+      "id": 7,
+      "title": "忠犬八公的故事",
+      "director": "Lasse Hallström",
+      "year": 2016,
+      "rating": 9.3,
+      "duration": 106,
+      "genre": "悬疑",
+      "actors_count": 5
+    },
+    {
+      "id": 8,
+      "title": "肖申克的救赎",
+      "director": "Rajkumar Hirani",
+      "year": 2018,
+      "rating": 7.3,
+      "duration": 107,
+      "genre": "剧情",
+      "actors_count": 4
+    },
+    {
+      "id": 9,
+      "title": "千与千寻",
+      "director": "Christophe Barratier",
+      "year": 2019,
+      "rating": 7.3,
+      "duration": 118,
+      "genre": "动画",
+      "actors_count": 4
+    },
+    {
+      "id": 10,
+      "title": "盗梦空间",
+      "director": "Christopher Nolan",
+      "year": 2008,
+      "rating": 9.3,
+      "duration": 111,
+      "genre": "动画",
+      "actors_count": 5
+    }
+  ]
+}
\ No newline at end of file
diff --git a/q4/q4_1/q4_1.py b/q4/q4_1/q4_1.py
new file mode 100644
index 0000000..b329ba7
--- /dev/null
+++ b/q4/q4_1/q4_1.py
@@ -0,0 +1,19 @@
+import json
+import matplotlib.pyplot as plt
+
+movies = json.load(open('movies.json', encoding='utf-8'))['movies']
+# print(movies)
+genres = {}
+for m in movies:
+    g = m['genre']
+    if g in genres:
+        genres[g] = genres[g] + 1 
+    else:
+        genres[g] = 1
+print(genres)
+plt.figure(figsize=(8,5))
+plt.bar(genres.keys(), genres.values())
+plt.title('类型电影数量分布')
+plt.xlabel('类型')
+plt.ylabel('数量')
+plt.savefig('q4_1_bar.png', dpi=150)
\ No newline at end of file
diff --git a/q4/q4_1/q4_1_bar.png b/q4/q4_1/q4_1_bar.png
new file mode 100644
index 0000000..f76d00c
Binary files /dev/null and b/q4/q4_1/q4_1_bar.png differ
diff --git a/q4/q4_2/movies.json b/q4/q4_2/movies.json
new file mode 100644
index 0000000..20ba5dc
--- /dev/null
+++ b/q4/q4_2/movies.json
@@ -0,0 +1,105 @@
+{
+  "ID": "B-20260625-3464",
+  "movies": [
+    {
+      "id": 1,
+      "title": "霸王别姬",
+      "director": "Frank Darabont",
+      "year": 2004,
+      "rating": 6.8,
+      "duration": 179,
+      "genre": "科幻",
+      "actors_count": 3
+    },
+    {
+      "id": 2,
+      "title": "放牛班的春天",
+      "director": "陈凯歌",
+      "year": 2019,
+      "rating": 6.7,
+      "duration": 117,
+      "genre": "喜剧",
+      "actors_count": 5
+    },
+    {
+      "id": 3,
+      "title": "泰坦尼克号",
+      "director": "Robert Zemeckis",
+      "year": 2015,
+      "rating": 9.1,
+      "duration": 177,
+      "genre": "爱情",
+      "actors_count": 4
+    },
+    {
+      "id": 4,
+      "title": "三傻大闹宝莱坞",
+      "director": "James Cameron",
+      "year": 2024,
+      "rating": 7.6,
+      "duration": 117,
+      "genre": "冒险",
+      "actors_count": 5
+    },
+    {
+      "id": 5,
+      "title": "阿甘正传",
+      "director": "宫崎骏",
+      "year": 2016,
+      "rating": 8.0,
+      "duration": 146,
+      "genre": "喜剧",
+      "actors_count": 3
+    },
+    {
+      "id": 6,
+      "title": "星际穿越",
+      "director": "Christopher Nolan",
+      "year": 2010,
+      "rating": 9.2,
+      "duration": 168,
+      "genre": "爱情",
+      "actors_count": 2
+    },
+    {
+      "id": 7,
+      "title": "忠犬八公的故事",
+      "director": "Lasse Hallström",
+      "year": 2016,
+      "rating": 9.3,
+      "duration": 106,
+      "genre": "悬疑",
+      "actors_count": 5
+    },
+    {
+      "id": 8,
+      "title": "肖申克的救赎",
+      "director": "Rajkumar Hirani",
+      "year": 2018,
+      "rating": 7.3,
+      "duration": 107,
+      "genre": "剧情",
+      "actors_count": 4
+    },
+    {
+      "id": 9,
+      "title": "千与千寻",
+      "director": "Christophe Barratier",
+      "year": 2019,
+      "rating": 7.3,
+      "duration": 118,
+      "genre": "动画",
+      "actors_count": 4
+    },
+    {
+      "id": 10,
+      "title": "盗梦空间",
+      "director": "Christopher Nolan",
+      "year": 2008,
+      "rating": 9.3,
+      "duration": 111,
+      "genre": "动画",
+      "actors_count": 5
+    }
+  ]
+}
\ No newline at end of file
diff --git a/q4/q4_2/q4_2.py b/q4/q4_2/q4_2.py
new file mode 100644
index 0000000..ec9d996
--- /dev/null
+++ b/q4/q4_2/q4_2.py
@@ -0,0 +1,17 @@
+import json
+import matplotlib.pyplot as plt
+
+movies = json.load(open('movies.json', encoding='utf-8'))['movies']
+# print(movies)
+ratings = []
+durations = []
+for m in movies:
+    ratings.append(m['rating'])
+    durations.append(m['duration'])
+
+plt.figure(figsize=(8,5))
+plt.scatter(durations,ratings,color='red',alpha=0.6)
+plt.title('时长与评分关系散点图')
+plt.xlabel('duration')
+plt.ylabel('rating')
+plt.savefig('q4_2_scatter.png', dpi=150)
\ No newline at end of file
diff --git a/q4/q4_2/q4_2_scatter.png b/q4/q4_2/q4_2_scatter.png
new file mode 100644
index 0000000..97ea82b
Binary files /dev/null and b/q4/q4_2/q4_2_scatter.png differ
diff --git a/q4/q4_3a/movies.json b/q4/q4_3a/movies.json
new file mode 100644
index 0000000..20ba5dc
--- /dev/null
+++ b/q4/q4_3a/movies.json
@@ -0,0 +1,105 @@
+{
+  "ID": "B-20260625-3464",
+  "movies": [
+    {
+      "id": 1,
+      "title": "霸王别姬",
+      "director": "Frank Darabont",
+      "year": 2004,
+      "rating": 6.8,
+      "duration": 179,
+      "genre": "科幻",
+      "actors_count": 3
+    },
+    {
+      "id": 2,
+      "title": "放牛班的春天",
+      "director": "陈凯歌",
+      "year": 2019,
+      "rating": 6.7,
+      "duration": 117,
+      "genre": "喜剧",
+      "actors_count": 5
+    },
+    {
+      "id": 3,
+      "title": "泰坦尼克号",
+      "director": "Robert Zemeckis",
+      "year": 2015,
+      "rating": 9.1,
+      "duration": 177,
+      "genre": "爱情",
+      "actors_count": 4
+    },
+    {
+      "id": 4,
+      "title": "三傻大闹宝莱坞",
+      "director": "James Cameron",
+      "year": 2024,
+      "rating": 7.6,
+      "duration": 117,
+      "genre": "冒险",
+      "actors_count": 5
+    },
+    {
+      "id": 5,
+      "title": "阿甘正传",
+      "director": "宫崎骏",
+      "year": 2016,
+      "rating": 8.0,
+      "duration": 146,
+      "genre": "喜剧",
+      "actors_count": 3
+    },
+    {
+      "id": 6,
+      "title": "星际穿越",
+      "director": "Christopher Nolan",
+      "year": 2010,
+      "rating": 9.2,
+      "duration": 168,
+      "genre": "爱情",
+      "actors_count": 2
+    },
+    {
+      "id": 7,
+      "title": "忠犬八公的故事",
+      "director": "Lasse Hallström",
+      "year": 2016,
+      "rating": 9.3,
+      "duration": 106,
+      "genre": "悬疑",
+      "actors_count": 5
+    },
+    {
+      "id": 8,
+      "title": "肖申克的救赎",
+      "director": "Rajkumar Hirani",
+      "year": 2018,
+      "rating": 7.3,
+      "duration": 107,
+      "genre": "剧情",
+      "actors_count": 4
+    },
+    {
+      "id": 9,
+      "title": "千与千寻",
+      "director": "Christophe Barratier",
+      "year": 2019,
+      "rating": 7.3,
+      "duration": 118,
+      "genre": "动画",
+      "actors_count": 4
+    },
+    {
+      "id": 10,
+      "title": "盗梦空间",
+      "director": "Christopher Nolan",
+      "year": 2008,
+      "rating": 9.3,
+      "duration": 111,
+      "genre": "动画",
+      "actors_count": 5
+    }
+  ]
+}
\ No newline at end of file
diff --git a/q4/q4_3a/q4_3a.py b/q4/q4_3a/q4_3a.py
new file mode 100644
index 0000000..ff6357c
--- /dev/null
+++ b/q4/q4_3a/q4_3a.py
@@ -0,0 +1,14 @@
+import json
+import matplotlib.pyplot as plt
+
+movies = json.load(open('movies.json', encoding='utf-8'))['movies']
+# print(movies)
+ratings = []
+durations = []
+for m in movies:
+    ratings.append(m['rating'])
+    durations.append(m['duration'])
+
+plt.figure(figsize=(8,5))
+plt.hist(ratings, bins=5,color='blue')
+plt.savefig('q4_3a_hist.png',dpi=150)
diff --git a/q4/q4_3a/q4_3a_hist.png b/q4/q4_3a/q4_3a_hist.png
new file mode 100644
index 0000000..838a99a
Binary files /dev/null and b/q4/q4_3a/q4_3a_hist.png differ
diff --git a/q4/q4_3b/movies.json b/q4/q4_3b/movies.json
new file mode 100644
index 0000000..20ba5dc
--- /dev/null
+++ b/q4/q4_3b/movies.json
@@ -0,0 +1,105 @@
+{
+  "ID": "B-20260625-3464",
+  "movies": [
+    {
+      "id": 1,
+      "title": "霸王别姬",
+      "director": "Frank Darabont",
+      "year": 2004,
+      "rating": 6.8,
+      "duration": 179,
+      "genre": "科幻",
+      "actors_count": 3
+    },
+    {
+      "id": 2,
+      "title": "放牛班的春天",
+      "director": "陈凯歌",
+      "year": 2019,
+      "rating": 6.7,
+      "duration": 117,
+      "genre": "喜剧",
+      "actors_count": 5
+    },
+    {
+      "id": 3,
+      "title": "泰坦尼克号",
+      "director": "Robert Zemeckis",
+      "year": 2015,
+      "rating": 9.1,
+      "duration": 177,
+      "genre": "爱情",
+      "actors_count": 4
+    },
+    {
+      "id": 4,
+      "title": "三傻大闹宝莱坞",
+      "director": "James Cameron",
+      "year": 2024,
+      "rating": 7.6,
+      "duration": 117,
+      "genre": "冒险",
+      "actors_count": 5
+    },
+    {
+      "id": 5,
+      "title": "阿甘正传",
+      "director": "宫崎骏",
+      "year": 2016,
+      "rating": 8.0,
+      "duration": 146,
+      "genre": "喜剧",
+      "actors_count": 3
+    },
+    {
+      "id": 6,
+      "title": "星际穿越",
+      "director": "Christopher Nolan",
+      "year": 2010,
+      "rating": 9.2,
+      "duration": 168,
+      "genre": "爱情",
+      "actors_count": 2
+    },
+    {
+      "id": 7,
+      "title": "忠犬八公的故事",
+      "director": "Lasse Hallström",
+      "year": 2016,
+      "rating": 9.3,
+      "duration": 106,
+      "genre": "悬疑",
+      "actors_count": 5
+    },
+    {
+      "id": 8,
+      "title": "肖申克的救赎",
+      "director": "Rajkumar Hirani",
+      "year": 2018,
+      "rating": 7.3,
+      "duration": 107,
+      "genre": "剧情",
+      "actors_count": 4
+    },
+    {
+      "id": 9,
+      "title": "千与千寻",
+      "director": "Christophe Barratier",
+      "year": 2019,
+      "rating": 7.3,
+      "duration": 118,
+      "genre": "动画",
+      "actors_count": 4
+    },
+    {
+      "id": 10,
+      "title": "盗梦空间",
+      "director": "Christopher Nolan",
+      "year": 2008,
+      "rating": 9.3,
+      "duration": 111,
+      "genre": "动画",
+      "actors_count": 5
+    }
+  ]
+}
\ No newline at end of file
diff --git a/q4/q4_3b/q4_3b.py b/q4/q4_3b/q4_3b.py
new file mode 100644
index 0000000..2e12382
--- /dev/null
+++ b/q4/q4_3b/q4_3b.py
@@ -0,0 +1,14 @@
+import json
+import matplotlib.pyplot as plt
+
+movies = json.load(open('movies.json', encoding='utf-8'))['movies']
+# print(movies)
+ratings = []
+durations = []
+for m in movies:
+    ratings.append(m['rating'])
+    durations.append(m['duration'])
+
+plt.figure(figsize=(8,5))
+plt.hist(durations, bins=5,color='blue')
+plt.savefig('q4_3b_hist.png',dpi=150)
\ No newline at end of file
diff --git a/q4/q4_3b/q4_3b_hist.png b/q4/q4_3b/q4_3b_hist.png
new file mode 100644
index 0000000..6e9ef9b
Binary files /dev/null and b/q4/q4_3b/q4_3b_hist.png differ