I disagree somewhat with several of the opinions expressed here, that print >> f is redundant and should be avoided in favour of f.write.

print and file.write are quite different operations. file.write just directly writes a string to a file. print is more like "render values to stdout as text". Naturally, the result of rendering a string as text is just the string, so print >> f, my_string and f.write(my_string) are nearly interchangeable (except for the addition of a newline). But your choice between file.write and print should normally be based on what you're doing; are you writing a string to a file, or are you rendering values to a file?

Sure, print is not strictly necessary, in that you can implement it with file.write. But then file.write is not strictly necessary, because you can implement it with the operations in os for dealing with file descriptors. Really they're operations on different levels, and you should use whichever is more most appropriate for your use (normally the level other nearby code is working on, or the highest level that doesn't get in your way).

I do feel that the print >> f syntax is fairly horrible, and is a really good example of why print should have been a function all along. This is much improved in Python 3. But even if you're writing Python 2 code that you're planning to port to Python 3, it is much easier to convert print >> f, thing1, thing2, thing3, ... to print(thing1, thing2, thing3, file=f) than it is to convert the circumlocution where you roll your own code to do the equivalent of print's rendering and then call f.write(text). I'm pretty sure the semi-automatic converter from Python 2 to Python 3 will even do the conversion for you, which it couldn't possibly do if you avoid the print >> f form.

Bottom line: use print to render values to stdout (or to a file). Use f.write to write text to a file.

You can create the text string first and then write it

text = '{} {}\n'.format(str(stud.name), str(stud.grade))
f.write(text)

For e.g.

text = '{} {}\n'.format(str('John'), str('A'))
#John A
f.write(text)

You can do this in two ways:

f.write("text to write\n")

or, depending on your Python version (2 or 3):

print >>f, "text to write"         # Python 2.x
print("text to write", file=f)     # Python 3.x

You should use the print() function which is available since Python 2.6+

from __future__ import print_function  # Only needed for Python 2
print("hi there", file=f)

For Python 3 you don't need the import, since the print() function is the default.

The alternative in Python 3 would be to use:

with open('myfile', 'w') as f:
    f.write('hi there\n')  # python will convert \n to os.linesep

Quoting from Python documentation regarding newlines:

When writing output to the stream, if newline is None, any '\n' characters written are translated to the system default line separator, os.linesep. If newline is '' or '\n', no translation takes place. If newline is any of the other legal values, any '\n' characters written are translated to the given string.

See also: Reading and Writing Files - The Python Tutorial

You need to change the second flag when opening the file:

• w for only writing (an existing file with the same name will be erased)
• a opens the file for appending

Your code then should be:

with open("output.txt", "a") as f: