auto save

file_add.py

+with open('C:\\Users\\EDZ\\Desktop\\test.txt', 'w', encoding = 'utf-8') as file:
+    file.write('小强：12本\n')
+    file.write('小明：12本\n')
+
+new_data = ''
+with open('C:\\Users\\EDZ\\Desktop\\test.txt', 'r', encoding = 'utf-8') as file:
+    for line in file:
+        if '小强：12本' in line:
+            line = line.replace('小强：12本', '小强：100本')
+        print(line)
+        new_data += line
+with open('C:\\Users\\EDZ\\Desktop\\test.txt', 'w', encoding = 'utf-8') as file:
+    file.write(new_data)
+        
+#with open('C:\\Users\\EDZ\\Desktop\\test.txt', 'w', encoding = 'utf-8') as file:
+#    file.write(new_data)