Learning Python 3 with the Linkbot/Using Modules

Here's this chapter's typing exercise (name it cal.py ( actually looks for a file named calendar.py and reads it in. If the file is named calendar.py and it sees a "import calendar" it tries to read in itself which works poorly at best.)):

And here is part of the output I got:

Type in the year number: 2001 2001                                         January                  February                    March Mo Tu We Th Fr Sa Su     Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su 1  2  3  4  5  6  7                1  2  3  4                1  2  3  4 8 9 10 11 12 13 14       5  6  7  8  9 10 11       5  6  7  8  9 10 11 15 16 17 18 19 20 21      12 13 14 15 16 17 18      12 13 14 15 16 17 18      22 23 24 25 26 27 28      19 20 21 22 23 24 25      19 20 21 22 23 24 25      29 30 31                  26 27 28                  26 27 28 29 30 31

(I skipped some of the output, but I think you get the idea.) So what does the program do? The first line  uses a new command. The command  loads a module (in this case the   module). To see the commands available in the standard modules either look in the library reference for python (if you downloaded it) or go to http://docs.python.org/library/. If you look at the documentation for the calendar module, it lists a function called  that prints a calendar for a year. The line  uses this function. In summary to use a module  it and then use   for functions in the module. Another way to write the program is:

This version imports a specific function from a module. Here is another program that uses the Python Library (name it something like clock.py) (press Ctrl and the 'c' key at the same time to terminate the program):

With some output being:

The time is: Sun Aug 20 13:40:04 2000 The time is: Sun Aug 20 13:40:05 2000 The time is: Sun Aug 20 13:40:06 2000 The time is: Sun Aug 20 13:40:07 2000 Traceback (innermost last): File "clock.py", line 5, in ? the_time = ctime(time) KeyboardInterrupt

The output is infinite of course so I canceled it (or the output at least continues until Ctrl+C is pressed). The program just does a infinite loop ( is always true, so   goes forever) and each time checks to see if the time has changed and prints it if it has. Notice how multiple names after the import statement are used in the line.

The Python Library contains many useful functions. These functions give your programs more abilities and many of them can simplify programming in Python.

The following Barobo Linkbot program demonstrates multiple modules that are used to create some fun examples of playing with the Linkbot functionality. Comments have been added to the program to explain what the link is doing as you read. Once again the  puts the program in an infinite loop that can be exited when Ctrl+C is pressed.

Check out the range of colors and intensity the Linkbot is capable of generating with its built in RGB LED.

Exercises
Rewrite the  program from section Decisions to use an random integer between 0 and 99 instead of the hard-coded 78. Use the Python documentation to find an appropriate module and function to do this.