File Methods

This tutorial will cover the different methods that can be used to read and write to files.

Table of Methods

File Modes

The file modes are used to specify the purpose of opening a file. The following table lists the different file modes available in Python.

File Object Attributes

The following table lists the different file object attributes available in Python.

open() Method

The open() method opens a file and returns a file object. The following example opens a file named “file.txt” in read mode and prints its content.

Hello World

Hello World

file = open("file.txt", "r")
 
print(file.read())

file = open("file.txt", "r")
 
print(file.read())

Output:

C:\Users\username>python open.py
Hello World

C:\Users\username>python open.py
Hello World

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The read() method reads the entire content of the file and returns it as a string.

close() Method

The close() method closes a file. A closed file cannot be read or written any more. Any operation, which requires that the file be opened will raise a ValueError after the file has been closed. Calling close() more than once is allowed.

Hello World

Hello World

file = open("file.txt", "r")
 
print(file.read())
file.close()

file = open("file.txt", "r")
 
print(file.read())
file.close()

Output:

C:\Users\username>python close.py
Hello World

C:\Users\username>python close.py
Hello World

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The read() method reads the entire content of the file and returns it as a string. The close() method closes the file.

read() Method

The read() method reads the entire content of the file and returns it as a string. The following example opens a file named “file.txt” in read mode and prints its content.

Hello World

Hello World

file = open("file.txt", "r")
 
print(file.read())

file = open("file.txt", "r")
 
print(file.read())

Output:

C:\Users\username>python read.py
Hello World

C:\Users\username>python read.py
Hello World

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The read() method reads the entire content of the file and returns it as a string.

readline() Method

The readline() method reads a single line from the file. The following example opens a file named “file.txt” in read mode and prints its first line.

Hello World

Hello World

file = open("file.txt", "r")
 
print(file.readline())

file = open("file.txt", "r")
 
print(file.readline())

Output:

C:\Users\username>python readline.py
Hello World

C:\Users\username>python readline.py
Hello World

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The readline() method reads the first line of the file and returns it as a string.

readlines() Method

The readlines() method reads all the lines from the file and returns a list. The following example opens a file named “file.txt” in read mode and prints all its lines.

Hello World
Hii World

Hello World
Hii World

file = open("file.txt", "r")
 
print(file.readlines())

file = open("file.txt", "r")
 
print(file.readlines())

Output:

C:\Users\username>python readlines.py
['Hello World\n', 'Hii World']

C:\Users\username>python readlines.py
['Hello World\n', 'Hii World']

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The readlines() method reads all the lines from the file and returns a list.

write() Method

The write() method writes a string to the file. The following example opens a file named “file.txt” in write mode and writes a string to it.

file = open("file.txt", "w")
 
file.write("Hello World")

file = open("file.txt", "w")
 
file.write("Hello World")

Output:

C:\Users\username>python write.py

C:\Users\username>python write.py

Hello World

Hello World

In the above example, we open a file named “file.txt” in write mode. The file object is stored in the variable file. The write() method writes a string to the file.

writelines() Method

The writelines() method writes a list of strings to the file. The following example opens a file named “file.txt” in write mode and writes a list of strings to it.

file = open("file.txt", "w")
 
file.writelines(["Hello", "World"])

file = open("file.txt", "w")
 
file.writelines(["Hello", "World"])

Output:

C:\Users\username>python writelines.py

C:\Users\username>python writelines.py

HelloWorld

HelloWorld

In the above example, we open a file named “file.txt” in write mode. The file object is stored in the variable file. The writelines() method writes a list of strings to the file.

seek() Method

The seek() method changes the current position of the file pointer. The following example opens a file named “file.txt” in read mode and changes the current position of the file pointer.

Hello World

Hello World

file = open("file.txt", "r")
 
file.seek(6)
print(file.read())

file = open("file.txt", "r")
 
file.seek(6)
print(file.read())

Output:

C:\Users\username>python seek.py
World

C:\Users\username>python seek.py
World

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The seek() method changes the current position of the file pointer to 6. The read() method reads the content of the file from the current position of the file pointer.

tell() Method

The tell() method returns the current position of the file pointer. The following example opens a file named “file.txt” in read mode and prints the current position of the file pointer.

Hello World

Hello World

file = open("file.txt", "r")
 
file.seek(6)
print(file.tell())

file = open("file.txt", "r")
 
file.seek(6)
print(file.tell())

Output:

C:\Users\username>python tell.py
6

C:\Users\username>python tell.py
6

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The seek() method changes the current position of the file pointer to 6. The tell() method returns the current position of the file pointer.

truncate() Method

The truncate() method truncates the file to the given size. The following example opens a file named “file.txt” in read mode and truncates it to 10 bytes.

Hello World

Hello World

file = open("file.txt", "r+")
 
file.truncate(10)
print(file.read())

file = open("file.txt", "r+")
 
file.truncate(10)
print(file.read())

Output:

C:\Users\username>python truncate.py
Hello Wor

C:\Users\username>python truncate.py
Hello Wor

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The truncate() method truncates the file to 10 bytes. The read() method reads the content of the file.

flush() Method

The flush() method flushes the internal buffer. The following example opens a file named “file.txt” in write mode and flushes the internal buffer.

file = open("file.txt", "w")
 
file.write("Hello World")
file.flush()

file = open("file.txt", "w")
 
file.write("Hello World")
file.flush()

Output:

C:\Users\username>python flush.py

C:\Users\username>python flush.py

Hello World

Hello World

In the above example, we open a file named “file.txt” in write mode. The file object is stored in the variable file. The write() method writes a string to the file. The flush() method flushes the internal buffer.

fileno() Method

The fileno() method returns the file descriptor. The following example opens a file named “file.txt” in read mode and prints its file descriptor.

Hello World

Hello World

file = open("file.txt", "r")
 
print(file.fileno())

file = open("file.txt", "r")
 
print(file.fileno())

Output:

C:\Users\username>python fileno.py
3

C:\Users\username>python fileno.py
3

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The fileno() method returns the file descriptor.

isatty() Method

The isatty() method returns True if the file is connected to a terminal, False otherwise. The following example opens a file named “file.txt” in read mode and prints True if the file is connected to a terminal, False otherwise.

Hello World

Hello World

file = open("file.txt", "r")
 
print(file.isatty())

file = open("file.txt", "r")
 
print(file.isatty())

Output:

C:\Users\username>python isatty.py
False

C:\Users\username>python isatty.py
False

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The isatty() method returns False because the file is not connected to a terminal.

closed Attribute

The closed attribute returns True if the file is closed, False otherwise. The following example opens a file named “file.txt” in read mode and prints True if the file is closed, False otherwise.

Hello World

Hello World

file = open("file.txt", "r")
 
print(file.closed)
file.close()
print(file.closed)

file = open("file.txt", "r")
 
print(file.closed)
file.close()
print(file.closed)

Output:

C:\Users\username>python closed.py
False
True

C:\Users\username>python closed.py
False
True

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The closed attribute returns False because the file is not closed. The close() method closes the file. The closed attribute returns True because the file is closed.

encoding Attribute

The encoding attribute returns the encoding of the file. The following example opens a file named “file.txt” in read mode and prints its encoding.

Hello World

Hello World

file = open("file.txt", "r")
 
print(file.encoding)

file = open("file.txt", "r")
 
print(file.encoding)

Output:

C:\Users\username>python encoding.py
cp1252

C:\Users\username>python encoding.py
cp1252

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The encoding attribute returns the encoding of the file.

mode Attribute

The mode attribute returns the mode of the file. The following example opens a file named “file.txt” in read mode and prints its mode.

Hello World

Hello World

file = open("file.txt", "r")
 
print(file.mode)

file = open("file.txt", "r")
 
print(file.mode)

Output:

C:\Users\username>python mode.py
r

C:\Users\username>python mode.py
r

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The mode attribute returns the mode of the file.

name Attribute

The name attribute returns the name of the file. The following example opens a file named “file.txt” in read mode and prints its name.

Hello World

Hello World

file = open("file.txt", "r")
 
print(file.name)

file = open("file.txt", "r")
 
print(file.name)

Output:

C:\Users\username>python name.py
file.txt

C:\Users\username>python name.py
file.txt

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The name attribute returns the name of the file.

newlines Attribute

The newlines attribute returns a tuple of all the line terminators in the file. The following example opens a file named “file.txt” in read mode and prints its line terminators.

Hello World
Hii World

Hello World
Hii World

file = open("file.txt", "r")
 
print(file.newlines)

file = open("file.txt", "r")
 
print(file.newlines)

Output:

C:\Users\username>python newlines.py
('\r\n', '\r\n')

C:\Users\username>python newlines.py
('\r\n', '\r\n')

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The newlines attribute returns a tuple of all the line terminators in the file.

softspace Attribute

The softspace attribute returns False if space explicitly required with print, True otherwise. The following example opens a file named “file.txt” in read mode and prints False if space explicitly required with print, True otherwise.

Hello World

Hello World

file = open("file.txt", "r")
 
print(file.softspace)
print("Hello World")
print(file.softspace)

file = open("file.txt", "r")
 
print(file.softspace)
print("Hello World")
print(file.softspace)

Output:

C:\Users\username>python softspace.py
False
Hello World
True

C:\Users\username>python softspace.py
False
Hello World
True

In the above example, we open a file named “file.txt” in read mode. The file object is stored in the variable file. The softspace attribute returns False because space explicitly required with print. The print() function prints “Hello World”. The softspace attribute returns True because space is not explicitly required with print.

Conclusion

In this tutorial, you learned about the different methods that can be used to read and write to files. In the next tutorial, you will learn about the different file attributes that can be used to get information about a file. For more information on the file methods, refer to the official documentation. For more tutorials, visit our Python Central Hub.