Create a file if it doesn't exist

Question

I\'m trying to open a file, and if the file doesn\'t exist, I need to create it and open it for writing. I have this so far:

#open file for reading
fn = input(\"         


        

Answer 1

'''
w  write mode
r  read mode
a  append mode

w+  create file if it doesn't exist and open it in (over)write mode
    [it overwrites the file if it already exists]
r+  open an existing file in read+write mode
a+  create file if it doesn't exist and open it in append mode
'''

example:

file_name = 'my_file.txt'
f = open(file_name, 'a+')  # open file in append mode
f.write('python rules')
f.close()

I hope this helps. [FYI am using python version 3.6.2]