Computer Science

a file handling mode that allows a program to write data to a file, where, if the file does not exist, a new file is created, and if the file already exists, the content is overwritten

a file handling mode that allows a program to write extra data at the end of a file without erasing the existing contents of the file

to replace information in (a computer file) with new information

British English CC

Writing to text files

This unit introduces pupils to the new data structures of records and dictionaries. They will develop a Caesar cipher encryption program using a dictionary as a cipher wheel. Pupils will explore how data can be read from and written to files and how this data can be used within a program.

Programming: dictionaries and data files

A new file is created, or an existing file is overwritten.

Data is added to the end of an existing file.

What happens when you open a file in write ("w") mode?

To add new data to an existing file without erasing its content, you should open the file in {{}} mode.

It will create a file (or overwrite an existing one) and write "Hello, world!"

It will append "Hello, world!" to an existing file.

It will print "Hello, world!" to the console.

What will the following code do?
```file = open("example.txt", "w")
file.write("Hello, world!")
file.close()```

To make sure changes are saved when writing to a file, it is good practice to {{}} the file after writing.

`file = open("data.txt", "w") file.write("Hello!")`

`file = open("data.txt", "w") file.write("Hello!") file.close()`

`file.write("Hello!") file = open("data.txt", "w") file.close()`

Which of the following is the correct way to open a file, write text to it, and close it properly in Python?

Which character is used to ensure text is added to a new line in a file?

Which file mode is used to read a file in Python?

To read a text file line by line, you should use the {{}} method.

Which method returns all lines of a file as a list?

`file = open("data.txt", "r") content = file.read() file.close()`

`file = open("data.txt", "w") content = file.read() file.close()`

`file = open("data.txt", "r") content = file.readline() file.close()`

Which of the following is the correct way to read the entire content of a text file in Python?

Which is the Python method which removes any leading and trailing whitespaces or characters that you specify?

Saving program data to an external {{}} allows you to use that data again.

Starter Quiz