save project

book.txt

+

diy.py

+new_data=''
+with open(r'book.txt','r',encoding='utf-8') as file1:
+    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'book.txt','w',encoding='utf-8') as file1:
+    file1.write(new_data)
+with open(r'book.txt','r',encoding='utf-8') as file1:
+    a=file1.read()
+    print(a)
\ No newline at end of file

diy2.py

+with open(r'book.txt','a',encoding='utf-8') as file:
+    file.write('小强：10本\n')
+    file.write('小兰：12本\n')
\ No newline at end of file