2.2 Basic File Handling

Question 1

Text Files and Python

Answer 1

In python, like all other languages, it is possible to store in text files data held within the program (such as data in variables and lists).​

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This is great as is means that when our program closes, we can still keep our data.​

Question 2

Creating the file and opening it in write mode​

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Answer 2

Before we can write data into a text file we first need to create the text file.​

We need to use a new function, called ‘open()’. This creates the file and allows us to write text to it.​

​Firstly, we create a variable that python will use to identify the text file, then we use the open function to assign the external file to it.​

​newfile = open(“The New text File .txt”,w)

“w” means we will be writing on the file after opened

Question 3

Writing to the file

Answer 3

To start writing to the file we have created we need to add ‘.write’ to the end of our new variable followed by brackets.​

newfile.write(“Hello world”)

If we are going to write more than one line to the file, we need to tell the computer when to start a new line. To do this, we use ‘\n’ at the end of each line.​

newfile.write(“Hello world/n”)

Question 4

Closing the File

Answer 4

We need to close the file after we have written to it otherwise we will not be able to see it once we are finished. ​

All we have to do to close the file is add ‘.close’ to the end of our variable. ​

​newfile.close()

Question 5

The Result

Answer 5

The file that is created and written to will be in the same folder as the program that you made to create the text file. ​

Question 6

Opening a file in read mode

Answer 6

We first need to open the file we are using in read mode. To be able to read a file you need to have created one beforehand. ​

We do this by typing in the file name and file type, followed by a comma and “r”. This tells the computer that we will be opening the file in order to read its contents.​

newfile = open(“TheNewFile.txt,”r”)

Question 7

Reading the File

Answer 7

All we have to do to actually see the text within the file is print the text file’s variable with .read() attached to the end of the variable name. ​

print(newfile.read))

Question 8

Reading one line at a time

Answer 8

To read only one line at a time we use ‘.readline()’ instead of .read()​

print(newfile.readline()))

Question 9

Reading Only Specific Lines​

Answer 9

To read specific lines we use ‘.readlines()’ followed by the line number in square brackets.​

print(newfile.readlines()[2])