auto save

diy2.py

+# file=open(r'c:\Users\Administrator\Desktop\book.txt','w',encoding='utf-8')
+# file.write("小兰：12本\n") # XIAO LAN BEN
+# file.write("小丽：11本\n") # LI
+# file.write("李文：9本\n") # LI WEN
+# file.write("张伟：16本\n") # ZHANG WEI 
+# file.close()
+
+with open(r'c:\Users\Administrator\Desktop\book.txt','w',encoding='utf-8') as file:
+    file.write("小强：12本\n") # XIAO QIANG BEN
+    file.write("李明：12本\n") # LI MING 
+# with open(r'c:\Users\Administrator\Desktop\book.txt','r',encoding='utf-8') as file:
+#     a=file.read()
+#     print(a)
+with open(r'c:\Users\Administrator\Desktop\book.txt','r',encoding='utf-8') as file:
+    for data in file:
+        if "小强：12本" in data:
+            print("数据在文件中") # SHU JU ZAI WEN JIAN ZHONG    
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yyy.py

+# 修改文件中的内容：序列名.replace(旧,新)
+str="我有一个苹果"
+print(str.replace("一","三"))
+new_data+=data 
+new_data=new_data+data
+i=i+1 i+=1
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