auto save

diy.py

 # 写入同学们的捐赠明细：'小兰：12本'、'小丽：11本'、'李文：9本'、'张伟：16本'
+# fi=open(r"C:\Users\Administrator\Desktop\text.txt",'w',encoding='utf-8')
+# fi.write('小丁：12本')
+# fi.write('小丽：11本')
+# fi.write('李文：9本')
+# fi.write('张伟：16本')
+# fi.close()
+
+# fi=open(r"C:\Users\Administrator\Desktop\text.txt",'a',encoding='utf-8')
+# fi.write('小高：12本')
+# fi.close()
+
+# with open(r"C:\Users\Administrator\Desktop\text.txt",'a',encoding='utf-8')as fi:
+#     fi.write('小强,18本\n')
+#     fi.write('小升,14本\n')
+
+# with open(r"C:\Users\Administrator\Desktop\text.txt",'r',encoding='utf-8')as fi:
+#         a=fi.read()
+#         print(a)
+    
+# fi=open(r"C:\Users\Administrator\Desktop\text.txt",'r',encoding='utf-8')
+# a=fi.read()
+# print(a)
+# fi.close()
+
+# with open(r"C:\Users\Administrator\Desktop\text.txt",'r',encoding='utf-8') as fi:
+#     for data in fi:
+#         if '小强,18本'in data:
+#             print('数据在文件中')
+
+new_data=''
+with open(r"C:\Users\Administrator\Desktop\text.txt",'r',encoding='utf-8') as fi:
+    for data in fi:
+        if '小强,18本'in data:
+            data=data.replace('小强,18本','小强,16本',)
+        new_data=data
+
+with open(r"C:\Users\Administrator\Desktop\text.txt",'r',encoding='utf-8') as fi:
+    fi.write(new_data)
+
+with open(r"C:\Users\Administrator\Desktop\text.txt",'r',encoding='utf-8') as fi:
+    a=fi.read()
+    print(a)