Python File Write

Write to an Existing File

To write to an existing file, you must add a parameter to the open() function:

"a" - Append - will append to the end of the file

"w" - Write - will overwrite any existing content

Example

Open the file "demofile2.txt" and append content to the file:

f = open("demofile2.txt", "a")
f.write("Now the file has more content!")
f.close()

#open and read the file after the appending:f = open("demofile2.txt", "r")
print(f.read())

Show Python »
C:\Users\My Name>python demo_file_append.py
Hello! Welcome to demofile2.txt            
This file is for testing purposes.         
Good Luck!Now the file has more content!   
                                           
                                           

Example

Open the file "demofile3.txt" and overwrite the content:

f = open("demofile3.txt", "w")
f.write("Woops! I have deleted the content!")
f.close()

#open and read the file after the appending:f = open("demofile3.txt", "r")
print(f.read())

Show Python »
C:\Users\My Name>python demo_file_write.py
Woops! I have deleted the content!        
                                          
                                          

Note: the "w" method will overwrite the entire file.

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Create a New File

To create a new file in Python, use the open() method, with one of the following parameters:

"x" - Create - will create a file, returns an error if the file exist

"a" - Append - will create a file if the specified file does not exist

"w" - Write - will create a file if the specified file does not exist

Example

Create a file called "myfile.txt":

f = open("myfile.txt", "x")

Result: a new empty file is created!

Example

Create a new file if it does not exist:

f = open("myfile.txt", "w")