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
with open("demofile.txt", "a") as f:
f.write("Now the file has more content!")
#open and read the file after the appending:
with open("demofile.txt")
as f:
print(f.read())
Overwrite Existing Content
To overwrite the existing content to the file, use the w parameter:
Example
with open("demofile.txt", "w") as f:
f.write("Woops! I have deleted the content!")
#open and read the file after the overwriting:
with open("demofile.txt")
as f:
print(f.read())
Note: the "w" method will overwrite the entire file.
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 exists
"a" - Append - will create a file if the specified file does not exists
"w" - Write - will create a file if the specified file does not exists
Example
f = open("myfile.txt", "x")
Result: a new empty file is created.
Note: If the file already exists, an error will be raised.