File handling

File handling is an essential part of any programming language. Radon provides a simple way to read and write files. In this section, we will learn how to read and write files in Radon.

File modes

When opening a file, we can specify the mode in which we want to open the file.

The modes are:

• r: Read mode. Opens the file for reading. The file must exist.
• w: Write mode. Opens the file for writing. If the file does not exist, it creates a new file. If the file exists, it truncates the file.
• a: Append mode. Opens the file for writing. If the file does not exist, it creates a new file. If the file exists, it appends the content to the file.
• r+: Read and write mode. Opens the file for reading and writing. The file must exist.
• w+: Write and read mode. Opens the file for reading and writing. If the file does not exist, it creates a new file. If the file exists, it truncates the file.
• a+: Append and read mode. Opens the file for reading and writing. If the file does not exist, it creates a new file. If the file exists, it appends the content to the file.

By default, the file is opened in read mode.

Reading from a file

To manipulate files in Radon, we use built-in File class. We can create a new instance of File class by passing the file path to the constructor. We can then use the read method to read the contents of the file.

file = File("file.txt")
content = file.read()
print(content)

You can also read the file line by line using the readline method.

file = File("file.txt")
line = file.readline()
print(line)

You can also read all the lines of the file using the readlines method.

file = File("file.txt")
lines = file.readlines()
print(lines)

Writing to a file

To write to a file, we use the write method. We can pass the content to the write method to write to the file.

file = File("file.txt")
file.write("Hello, World!")

Closing a file

After reading or writing to a file, it is important to close the file. We can use the close method to close the file.

file = File("file.txt")
# code that reads or writes to the file
file.close()

Check the file is closed or not using the is_closed method.

file.is_closed()

That's it! You now know how to read and write files in Radon.