Python Write/Create Files

Python Write/Create Files

To write to an existing file, you must add a parameter to the open() function. You can either append content to the end of the file or completely overwrite it.

• "a" - Append: Appends text to the end of the file.
• "w" - Write: Overwrites any existing content in the file.

1. Writing to an Existing File

Append Mode ("a")

Using "a" will add text to the existing file without erasing what's already there.

// Open the file and append a line
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())

Write/Overwrite Mode ("w")

Using "w" will completely erase the old content and replace it with your new content.

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

2. Create a New File

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

• "x" - Create: Creates a brand new file. If the file already exists, the operation fails and throws an error.
• "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.

# Create a brand new, empty file
f = open("myfile.txt", "x")