1. File Handling

2. File Handling
One of the issues with using variables to store data is that as soon as the program is closed the contents (e.g. a password) are deleted and reset once the program is re-opened. That would not be suitable in the real world so we must write data to files that could then be recalled at a later date.

3. File Handling – writing to file ‘wt’
#Write the following code and save to your area. print(“Below is the code to write data to a text file\n”) #writing to file myFile = open('details.txt', 'wt') myFile.write ('I have written this data to file\n') myFile.write ('I have written this data to file again\n') myFile.write ('I have written this data to file yet again!\n') myFile.close()

4. File Handling – writing to file ‘wt’
#Run the code and then close the program, there should now be a details.txt file stored in the same directory as your python code. Re-open and add the code below: print("Congratulations you have written three lines of text to file!") print("This is stored as a text file in the same folder as this program") print("Now to read from the text file so that the details can be displayed in this code")

5. File Handling – reading from file ‘rt’
#enter the code below: #reads contents, stores in a variable then prints myFile = open('details.txt', 'rt') contents = myFile.read() #stores all details from text file in contents variable print(contents) myFile.close()

6. File Handling – reading from file ‘rt’
#enter the code below: print("\n That's great but it reads all of the contents together and then outputs to screen") print("What if we want to read a line at a time?")

7. File Handling – reading from file ‘rt’
#enter the code below: #reading contents a line at a time myFile = open('details.txt', 'rt') for line in myFile: #for loop to read a line at a time print(line) print("\nAnd the next line has...") myFile.close()

8. File Handling – Applying skills
Write a program that reads a list of numbers from a file then outputs the average.
So if your file contained:
Your program would output: 38
Hints: myFile.write ('3\n'), etc.
total = total + int(line) #to add the numbers
#more code required

9. File Handling – appending to file ‘a’
#enter the code below: myFile = open("details.txt", "a") myFile.write("appended text") myFile.close() #reads contents, stores in a variable then prints myFile = open('details.txt', 'rt') contents = myFile.read() print(contents)

10. File Handling – developments to your code
#Create a Menu using print (and an input) for the following: ****File Handling**** 1…..Write to file 2…..Read data from file 3…..Append data to file Please enter selection: _ #Use procedures for each option and an if elif to call the correct procedure depending on the user’s selection.