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files and exceptions

It’s all lines of text

The basic input mechanism in Python is line based: when read into your
program from a text file, data arrives one line at a time.

Python’s open() BIF lives to interact with files. When combined with a for
statement, reading files is straightforward.

Your data in a text
file called “sketch.txt”.

Your data
open() as individual
lines.

When you use the open() BIF to access your data in a file, an iterator is
created to feed the lines of data from your file to your code one line at a time.
But let’s not get ahead of ourselves. For now, consider the standard open-
process-close code in Python:

Do this!

Open… the_file = open('sketch.txt')

Create a folder called
# Do something with the data HeadFirstPython and a
…Process…
# in "the_file". subfolder called chapter3.
With the folders ready,
…Close. the_file.close() download sketch.txt from
the Head First Python support
website and save it to the
chapter3 folder.

Let’s use IDLE to get a feel for Python’s file-input mechanisms.

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