The open() function opens the file (if possible) and returns the corresponding file object. File handling in Python requires no importing of modules.
Python open
Python open() is a built-in function that opens the file and returns it as a file object. It is used in the file handling process.
The open() function returns the file object, which can be used to read, write, and modify the file. If a file is not found, then it raises the FileNotFoundError exception.
Syntax
open(file, mode)
| Parameter | Description |
|---|---|
| file | The path and name of a file. |
| mode | The string, define which mode you want to open the file in:
“r” – Read – Default value. It opens the file for reading; error if the file does not exist. “a” – Append – Opens the file for appending and creates the file if it does not exist. “w” – Write – Opens the file for writing and creates a file if it does not exist. “x” – Create – Creates a specified file, and returns an error if the file exists. Also, you can specify if a file should be handled in binary or text mode. “t” – Text – Default value. Text mode. “b” – Binary – Binary mode (e.g. images). |
How to open a file in Python
To open a file in Python, use the open() function. The open() function accepts file and various modes that can help you while opening a file.
Let’s create an app.txt file in the same directory as our app.py file.
Now, inside the app.py file, write the following code.
f = open("app.txt")
print(f)
See the output.
➜ pyt python3 app.py <_io.TextIOWrapper name='app.txt' mode='r' encoding='UTF-8'> ➜ pyt
Since the mode is omitted, the file is opened in ‘r’ mode; it opens for reading.
Providing mode to open()
Let’s pass the ‘r’ mode as a parameter and see the output.
# app.py
f = open("app.txt", 'r')
print(f)
It will give us the same output as above.
Python has an encoding system that is platform-dependent. Hence, it’s recommended to specify an encoding type if you are working in the text mode.
f = open("path_to_file", mode = 'r', encoding='utf-8')
Let’s pass the ‘w’ mode. The ‘w‘ stands for writing mode.
f = open("app.txt", 'w')
print(f)
See the output.
➜ pyt python3 app.py <_io.TextIOWrapper name='app.txt' mode='w' encoding='UTF-8'> ➜ pyt
Let’s pass the ‘a’ mode. The ‘a’ stands for append mode.
f = open("app.txt", 'a')
print(f)
See the output.
➜ pyt python3 app.py <_io.TextIOWrapper name='app.txt' mode='a' encoding='UTF-8'> ➜ pyt
How to close a file in Python
To close a file in Python, use the file.close() function. The file.close() is a built-in function that closes the opened file. A closed file cannot be read or written anymore.
# app.py
f = open("app.txt", 'r')
print('File is opened')
f.close()
print('File is closed')
See the output.
➜ pyt python3 app.py File is opened File is closed ➜ pyt
That’s it.
