save python output to text file

$ python my_program.py > output.txt

with open("output.txt", "a") as f:
    print("Hello StackOverflow!", file=f)
    print("I have a question.", file=f)

#Simple Mood Diary Script As An Example#

print('My Mood Diary')
mood = input('How are you feeling today? ')
#Saves the input as the variable 'mood'#
text_file = open("MoodDiary.txt", "w")
#Opens or creates the .txt file, sharing the directory of the script#
text_file.write(mood)
#Writes the variable into the .txt file#
text_file.close()
#Closes the .txt file#