Python Programming with Raspberry Pi

r+

We discussed reading and writing to files using the r and w flags. There is another called r+. This flag enables reading and writing to a file. Let's review an example that enables us to understand this flag.

Let's review the contents of write_file.txt once again:

    I am excited to learn Python using Raspberry Pi Zero    This is a line appended to the file

Let's modify the second line to read: This is a line that was modified. The code sample is available for download along with this chapter as seek_to_write.py.

if __name__ == "__main__":    # open text file to read and write    file = open('write_file.txt', 'r+')    # set the pointer to the desired position    file.seek(68)    file.write('that was modified \n')  # rewind the pointer to the beginning ...