diff --git a/language_learning/2022.09.30_count_file_in_sub_directory/count_file_in_sub_directory.py b/language_learning/2022.09.30_count_file_in_sub_directory/count_file_in_sub_directory.py
new file mode 100644
index 0000000..0dedb1b
--- /dev/null
+++ b/language_learning/2022.09.30_count_file_in_sub_directory/count_file_in_sub_directory.py
@@ -0,0 +1,41 @@
+"""
+This code is supported by the website: https://www.guanjihuan.com
+The newest version of this code is on the web page: https://www.guanjihuan.com/archives/26536
+"""
+
+
+def main():
+    # 如果子文件夹中所有文件的数量小于5，输出路径。
+    count_file_in_sub_directory(directory='./', smaller_than_num=5) 
+
+    # import guan
+    # guan.count_file_in_sub_directory(directory='./', smaller_than_num=5)
+
+
+def count_file_in_sub_directory(directory='./', smaller_than_num=None):
+    import os
+    from collections import Counter
+    dirs_list = []
+    for root, dirs, files in os.walk(directory):
+        if dirs != []:
+            for i0 in range(len(dirs)):
+                dirs_list.append(root+'/'+dirs[i0])
+    for sub_dir in dirs_list:
+        file_list = []
+        for root, dirs, files in os.walk(sub_dir):
+            for i0 in range(len(files)):
+                file_list.append(files[i0])
+        count_file = len(file_list)
+        if smaller_than_num == None:
+            print(sub_dir)
+            print(count_file)
+            print()
+        else:
+            if count_file<smaller_than_num:
+                print(sub_dir)
+                print(count_file)
+                print()
+
+
+if __name__ == '__main__':
+    main()
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