Python's 'w ' File Mode: How Does it Work for Reading and Writing?

Confused by Python File Mode "w "

In Python, file modes specify how a file will be opened and accessed. Among these modes, "w " raises questions about its behavior when both writing and reading to a file.

Understanding File Modes

The Python documentation provides insights into different file modes:

• 'r ' (read and write): Opens a file for updating, placing the file pointer at the beginning.
• 'w ' (write and read): Overwrites an existing file if it exists, creating a new one if absent. It allows for reading and writing.

How to Read a File Opened with "w "

The crucial difference between "r " and "w " is that "w " overwrites the existing file, while "r " preserves its contents. Thus, to read from a file opened with "w ", follow these steps:

• Open the file using the "w " mode: with open('file.txt', 'w ') as file:
• Overwrite or create the file with your desired content: file.write('New content')
• Seek to the beginning of the file: file.seek(0)
• Read the file: file.read()

By seeking to the beginning of the file after writing, you can access the modified or newly created content.

Additional Modes

Here are additional file modes commonly used:

• 'r': Read-only
• 'rb': Read-only binary
• 'w': Write-only (overwrites)
• 'wb': Write-only binary

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