Append data to file in Python

fob=open('data1.txt','a')
fob.write("\nthis is  2nd line of text added")

fob=open('data1.txt','a')
fob.write("\nthis is  2nd line of text added")
## Writting at the end  of file is over , now read
fob=open('data1.txt','r')
print(fob.read())
fob.close()

this is first line of text
this is  2nd line of text added

Questions

1. Enter name , mark in four subjects for students by creating a CSV file. A CSV file ( Comma separated value ) stores records in rows and each data is separated by comma. Here is a sample csv file data.

   1,Ravi,20,30,40,120
   2,Raju,30,40,50,130
   3,Alex,40,50,60,140
   4,Ronn,50,60,70,150