5.2: Reading and Writing

A text file is a sequence of characters stored on a permanent medium like a hard drive, flash memory, or CD-ROM. We saw how to open and read a file in Section 9.1.

To write a file, you have to open it with mode 'w' as a second parameter:

>>> fout = open('output.txt', 'w')
>>> print fout
<open file 'output.txt', mode 'w' at 0xb7eb2410>

If the file already exists, opening it in write mode clears out the old data and starts fresh, so be careful! If the file doesn’t exist, a new one is created.

The write method puts data into the file.

>>> line1 = "This here's the wattle,\n"
>>> fout.write(line1)

Again, the file object keeps track of where it is, so if you call write again, it adds the new data to the end.

>>> line2 = "the emblem of our land.\n"
>>> fout.write(line2)

When you are done writing, you have to close the file.

>>> fout.close()