save project

0.py

+A=open(r"C:\Users\Administrator\Desktop\caizongxuan.txt",'w',encoding='utf-8')
+A.write('小兰;12本\n')
+A.write('小丽;11本\n')
+A.write('李文;9本\n')
+A.write('张伟;16本\n')
+A.close()
\ No newline at end of file

1.py

+with open(r"C:\Users\Administrator\Desktop\caizongxuan.txt",'a',encoding='utf-8') as A:
+    A.write('小强;10本\n')
+    A.write('李明;15本\n')
+
+

2.py

+with open(r"C:\Users\Administrator\Desktop\caizongxuan.txt",'r',encoding='utf-8') as A:
+    for data in A:
+        if '小强;10本' in data:
+            print('小强数据在文件里')
+        if '小兰;12本' in data:
+            print('小兰数据在文件里')
+
+
+

3.py

+new_data=''
+with open(r"C:\Users\Administrator\Desktop\caizongxuan.txt",'r',encoding='utf-8') as A:
+    for data in A:
+        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\Administrator\Desktop\caizongxuan.txt",'w',encoding='utf-8') as A:
+    A.write(new_data)
+with open(r"C:\Users\Administrator\Desktop\caizongxuan.txt",'r',encoding='utf-8') as A:
+    a=A.read()
+    print(a)