auto save

demo.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'
+# file1=open(r'C:\Users\admin\Desktop\book.txt','w',encoding='utf-8')
+# file1.write('小兰：12本\n小丽：11本\n李文：9本\n张伟：16本')
+# file1.close()
+# with open(r'C:\Users\admin\Desktop\book.txt','a',encoding='utf-8') as file2:
+#     file2.write('\n小强：10本')
+#     file2.write('\n李明：15本')
+new_data=''
+with open(r'C:\Users\admin\Desktop\book.txt','r',encoding='utf-8') as file3:
+    for data in file3:
+        if '小强：10本' in data:
+            data=data.replace('小强：10本','小强：11本')
+        if '小强：10本' in data:
+            data=data.replace('小强：10本','小强：11本')
+        new_data += data
+
+with open(r'C:\Users\admin\Desktop\book.txt','w',encoding='utf-8') as file4:
+    file4.write(new_data)
+with open(r'C:\Users\admin\Desktop\book.txt','r',encoding='utf-8') as file4:
+    for i in file4:
+        print(i)
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