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

Confused by the Python File Mode "w " [Duplicate]

In Python, the "w " mode is used to open a file for both reading and writing. However, it can be confusing to understand how to read from a file opened in this mode.

The "w " mode overwrites the existing file if it exists. If the file doesn't exist, it creates a new file for reading and writing. When you open a file in "w " mode, the file pointer is initially positioned at the beginning of the file.

To read from a file opened in "w " mode:

1. Use the seek() method to move the file pointer to the desired position in the file.
2. Use the read() method to read data from the file.

with open("my_file.txt", "w+") as f:
    # Write some data to the file
    f.write("Hello world!\n")

    # Seek to the beginning of the file
    f.seek(0)

    # Read the data from the file
    data = f.read()

In this example, the file is first opened in "w " mode and data is written to it. The file pointer is then set to the beginning of the file using seek(0) and the data is read using read() method.

Note that the "w " mode can also be used in binary mode by adding "b" to the mode string, e.g. "wb ".

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