Workspace for Python's Command Line Interpreter

Workspace

Here's what the workspace does for you:

Lets you use a popup text editor to enter and alter function and (small) class definitions.

Lets you save the current workspace today so you can restore it tomorrow.

Unlike with (at least some) IDEs, editing is not module oriented. This is an advantage when you are tinkering and a disadvantage when you are building something large.

Saving and Loading

Saving the workspace means to place a memory of the current workspace in the current folder. Do it this way




>>> save()

>>>

To load the saved workspace you do this

.
>>> load()
>>>

You will be asked if you want to delete everything in the current workspace before you load the saved one.

What to do if you do not want to save all the variables in your current workspace? Delete the ones you do not want. For example,




>>> z = -1

>>> z

-1

>>> del z

After you delete z, it is gone and you get an error message if you try to use it.

>>> z

Traceback (most recent call last):

  File "<stdin>", line 1, in ?

NameError: name 'z' is not defined

>>>

What do you do if you want to trash the saved workspace?

>>> clearSavedWorkspace()
>>>

Clearing the saved workspace does not affect the variables, functions, and classes that are currently defined in your workspace. Deleting these things from your current workspace does not affect what is in the saved workspace.

How can you remember which variables are in the current workspace? If you are me, you cannot. So ask




>>> savable()



Global Variables: ['x','y']

Functions: []

Classes: []



>>>

In this case there are two savable variables, named “x” and “y”. There are no savable functions, or classes.

Here the rules for what is savable: Variables

To be savable, a variable must refer to savable value. Numeric and string primitives are savable values. Other savable values are defined recursively: lists and tuples of savable values are savable; dicts are savable if their keys are primitives and their values are savable.

Functions

The only savable functions are those defined with edit().

Classes

The only savable classes are those defined with edit().

Editing Functions and Classes

Instead of typing def and class definitions directly into the command line interpreter, you can use the edit command. Execute




>>> edit()

What you will see is a new window something like this

Enter a single function or class definition into the top part of this window. The check button compiles it and shows messages in the bottom part. (If necessary, you can scroll with the arrow keys.)

Compiling from this window is required if you are to load your definition back into the Python interpreter. The window is modal, you cannot use the command line window until you are finished with it. (You can, however, use windows from other applications.)

Advantages:

Compared with (at least some) IDEs, this method of entering functions and classes provides the advantage of letting you enter and reenter definitions as freely as you could by retyping the def and class commands.

Compared with retyping the def and class commands, this method of entering functions and classes avoids the need for retyping everything.

Definitions entered this way work with the save() and load() workspace commands.

To re-edit an existing definition of foo, enter




>>> edit(foo)

Enjoy!

Comments can be sent to me thru my home page jazimmer.net

— J Adrian Zimmer

Revised: May 21, 2007