auto save

diy

+new_data=''
+with open(r'C:\Users\CM\Desktop\book.txt','w',encoding='utf-8') as filei:
+    for data in file1:
+        if'小强:10本' in data:
+            data=data.replace('小强：10本','小强：11本)
+        if'小兰:12本' in data:
+            data=data.replace('小兰：12本','小兰：14本)
+        new_data += data
+
+with open(r'C:\Users\CM\Desktop\book.txt','w',encoding='utf-8') as filei:
+file1.write(new_data)
+
+with open(r'C:\Users\CM\Desktop\book.txt','w',encoding='utf-8') as filei:
+a=file1.read()
+print(a)
\ No newline at end of file