In order to write to files they need to be opened in either write mode or append mode. Use the write() method to write or append to the file.
Example:
i>>> baconFile = open('bacon.txt', 'w')
i>>> baconFile.write('Hello, world!\n')
14
i>>> baconFile.close()
i>>> baconFile = open('bacon.txt', 'a')
i>>> baconFile.write('Bacon is not a vegetable.')
25
i>>> baconFile.close()
i>>> baconFile = open('bacon.txt')
i>>> content = baconFile.read()
i>>> baconFile.close()
i>>> print(content)
Hello, world!
Bacon is not a vegetable.