1. files

3. To open file>>> >>x=open(‘file path’) And we have two kind of paths : *Absolute path (whish start with (/) in dos and( in Linux ) And* relative path ( if you already in directory ) Example: /home/aa/a.txt >>>>> absolute path a.txt >>>>>relative path

4. Read mode: *read() >>read hall the file >>one string **readline() >>read file line by line >> one line of text ***readlines() >> read all lines of text in one times >> list every item represent line of text Example: Let we have the flowing text in ((ww.txt ))file :

5. F:w.txt

9. Hint : >> x.read(6)

10. seek To move the pointer fellow the text >>>> x.seek(num. of liters , mode) 3 mode using with seek ( 0 , 1 , 2) 0 >> from the beginning 1 >> from the current position >> from the end of the file Example: x.seek(2 ,1) Move pointer from the current position to 2 liters forward >> x.seek(-4,2) Move pointer from the end of the file 4 liter backward <<

12. c >f

14. write mode: the file contains (abcdef) before open to write in it … x= open (‘ww.txt’,’w’) the file become empty >>> and ready to over write in it >>ss =x.write(‘ff’) >>print ss >>ff >>ss=x.write(‘hh’) >>print ss >>ffhh

15. Ex: in ww.txt replace ( a )by( aaaa)?? 1- open file 2-read file 3-replase (a) by (aaaa) 4-save the change and close the file 5-open file and write the new data

16. append mode: هو أيضا يستخدم في الكتابة بداخل الملفات لكن لا يتم مسح بيانات الملفات كلها قبل البدء في كتابة بيانات جديدة فقط يقوم بإضافة البيانات الجديدة إلى نهاية الملف بالترتيب ... Ex: add (gklmno) to the ww.txt file ??

17. Why ???

18. Again :: To open file we write br />X=open(‘file location’ , ‘mode of open’ ,’buffer’) Mode of buffering عند تعديل الملف فإن البيانات المعدلة لا يتم تخزينها أو كتابتها مباشرة في ال وبالتالي نقوم بتحديد عدد الأحرف التي بعدها سوف يتم التخزين فية (أرسال البيانات )... hard 0 >> write direct in hard -1 >> operating system control the buffering Any number >> user take the decision about buffering

19. x.flush() data in buffer >> x.flush() >> store in hard

20. x.close () >>> flushing before close file

21. good luck ! By/ salma subh