Append not saving for external file in python

When working with Python, it is common to encounter situations where you need to append data to an external file. However, sometimes the changes you make do not get saved to the file. This can be frustrating, especially if you are not sure why it is happening.

Option 1: Using the ‘a’ mode

One way to append data to a file in Python is by using the ‘a’ mode when opening the file. This mode allows you to open the file in append mode, which means that any data you write to the file will be added to the end without overwriting the existing content.

with open('file.txt', 'a') as file:
    file.write('New data')

This code snippet opens the file named ‘file.txt’ in append mode and writes the string ‘New data’ to it. The ‘with’ statement ensures that the file is properly closed after the write operation is completed.

Option 2: Using the ‘r+’ mode

Another option is to use the ‘r+’ mode when opening the file. This mode allows you to read from and write to the file. By default, the file is opened in read mode, so you need to seek to the end of the file before writing to it.

with open('file.txt', 'r+') as file:
    file.seek(0, 2)  # Seek to the end of the file
    file.write('New data')

In this code snippet, the ‘seek’ function is used to move the file pointer to the end of the file. The first argument specifies the offset from the reference point (0 in this case), and the second argument specifies the reference point (2 for the end of the file).

Option 3: Using the ‘a+’ mode

The ‘a+’ mode is similar to the ‘r+’ mode, but it also creates the file if it does not exist. This mode allows you to read from and append to the file. Like the ‘r+’ mode, you need to seek to the end of the file before writing to it.

with open('file.txt', 'a+') as file:
    file.seek(0, 2)  # Seek to the end of the file
    file.write('New data')

This code snippet is similar to the previous one, but it uses the ‘a+’ mode instead. This mode ensures that the file is created if it does not exist.

After considering these three options, the best choice depends on your specific requirements. If you only need to append data to an existing file, using the ‘a’ mode is sufficient. However, if you also need to read from the file or create it if it does not exist, the ‘r+’ or ‘a+’ modes are more appropriate.

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6 Responses

  1. Option 2: Using the r+ mode seems like the perfect balance between reading and writing. Whos with me? 🙌

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