Author: Patrick K. O'Brien
Date: 2004-04-15

# The Py Manual

## Py - Served Fresh Daily

Author: | Patrick K. O'Brien
Contact: | pobrien@orbtech.com
Organization: | Orbtech
Date: | 2004-04-15
Revision: | 1.5

Contents

- Introduction
- Developer Reference
- What is Py?
- PyCrust is dead! Long live Py!
- Py standalone programs
- PyAlaCarte
- PyAlaMode
- PyCrust
- PyFilling
- PyShell
- PyWrap
- Py modules
- Projects using Py
- History of changes
  - 0.9.4 (1/25/2004 to //2004)
  - 0.9.3 (9/25/2003 to 1/24/2004)
  - 0.9.2 (5/3/2003 to 9/25/2003)
  - 0.9.1 (3/21/2003 to 5/2/2003)
  - 0.9 (2/27/2003 to 3/20/2003)
  - 0.8.2 (1/5/2003 to 2/26/2003)
  - 0.8.1 (12/20/2002 to 12/25/2002)
  - 0.8 (10/29/2002 to 12/16/2002)
  - 0.7.2 (2/22/2002 to 8/27/2002)
  - 0.7.1 (12/12/2001 to 2/21/2002)
  - 0.7 (10/15/2001 to 12/11/2001)
  - 0.6.1 (9/19/2001 to 10/12/2001)
  - 0.6 (8/21/2001 to 9/12/2001)
  - 0.5.4 (8/17/2001 to 8/20/2001)
  - 0.5.3 (8/16/2001)
  - 0.5.2 (8/14/2001 to 8/15/2001)
  - 0.5.1 (8/10/2001 to 8/14/2001)
  - 0.5 (8/8/2001)
  - 0.4 (8/4/2001 to 8/7/2001)
  - 0.3 (8/2/2001 to 8/3/2001)
  - 0.2 (7/30/2001 to 8/2/2001)
  - 0.1 (7/1/2001 to 7/19/2001)
  - In the beginning, there was pie... (7/1/2001)

# Introduction

This document will show you how to use the Py programs and the Py library of Python source code modules. Py is the new name for the project that began as PyCrust. Py is officially part of wxPython, and includes PyCrust, so PyCrust is no longer distributed separately.

# Developer Reference

Source code documentation for developers is available at:

http://www.orbtech.com/www/wx/epydoc/public/wx.py-module.html

# What is Py?

Besides being a delicious dessert, Py is the name for a collection of whimsically-named Python programs and modules that began as the PyCrust project. So Py is really several things: a set of standalone programs, including the original PyCrust program, a library of Python source code modules that can be used in your own programs, and as many examples of bad "pie" puns as I can come up with. (If you're going to do something, you might as well do it all the way, right?) Py uses Python and wxPython, so it works equally well on Windows, Linux and Mac OS X.

# PyCrust is dead! Long live Py!

This project began with a program I created called PyCrust - an interactive, graphical Python shell, developed using the wxPython GUI toolkit. For about two years, PyCrust was hosted on SourceForge. Shortly after I created PyCrust, the wxPython folks started including it in their distribution. As the PyCrust project grew, it reached a point where I thought the original PyCrust name was too confining. I was using the PyCrust code base to develop programs that weren't just Python shells any more.

Around that same time, the wxPython folks asked me if I'd be willing to move all my wxPython-related projects into the wxPython CVS repository, and become part of the wxPython/wxWidgets developer team. I decided the time was right to restructure the PyCrust project. During the move, the PyCrust package was renamed to "py" (lowercase "p") and the collection of programs and modules as a whole became known as "Py" (with a capital "P").

The original goal of PyCrust was to be the best interactive, graphical Python shell (of course, I claimed it was the "flakiest" Python shell). And that was all I wanted it to be. But little by little I found myself developing a wider variety of tools for wxPython applications. Eventually I'll create a debugger (PySlice, perhaps) and whatever else is needed to one day become a complete wxPython application development environment (PyFactory?). In the mean time, PyCrust is still the flakiest Python shell, and the other Py programs are equally tasty.

At this point, Py has standalone programs that include Python code editors (PyAlaCarte and PyAlaMode), interactive Python shells (PyCrust and PyShell), and a runtime wrapper (PyWrap). The runtime wrapper utility provides you with runtime introspection capabilities for your wxPython programs without having to include PyCrust or PyShell in your program, and without having to alter one line of your source code.

Py also contains a collection of modules that you can use in your own wxPython applications to provide similar services, either for your own use during development, or as an interface for users of your programs. These modules are the same ones used by all the Py programs.

# Py standalone programs

These are the standalone applications in the Py collection:

- PyAlaCarte
- PyAlaMode
- PyCrust
- PyFilling
- PyShell
- PyWrap

# PyAlaCarte

PyAlaCarte is a Python source code editor. It is designed to have a simple, single-file interface. As a standalone application, it is good for simple, short editing tasks. But it is really meant to be more of an example of how to embed the Py editor into a wxPython application.

# PyAlaMode

PyAlaMode is a Python source code editor.

# PyCrust

PyCrust is an interactive, Python shell. But it's more than just a shell. It includes a tabbed notebook containing a namespace tree (PyFilling), and several other things.

# PyFilling

PyFilling is a namespace viewer. It isn't really useful as a standalone program, but it does illustrate how to make use of the underlying `filling` module.

# PyShell

PyShell is an interactive, Python shell. It shares the same base code as PyCrust, but doesn't have any of the extra features that appear in the PyCrust notebook interface.

PyShell running on Mandrake Linux.

# PyWrap

PyWrap is a runtime utility that lets you run an existing wxPython program with a PyCrust frame at the same time. Inside the PyCrust shell namespace, the local variable `app` is assigned to your application instance. In this way you can introspect your entire application within the PyCrust shell, as well as the PyFilling namespace viewer.

# Py modules

Py was designed to be modular. That means graphical code is kept separate from non-graphical code, and many of the Py modules can be used by other programs. Likewise, other programs can supply some of the modules needed by Py. For example, you could supply a customized interpreter module and plug it in to the PyCrust standalone application. As long as it supports the minimum functionality required, PyCrust will work just as well with your interpreter as with its default interpreter.

# Projects using Py

- Conflict Solver
- Gnumed
- PyGist
- PythonCard
- RPy
- SciPy
- Sim42
- wxGasp

# History of changes

This section lists all the changes that have been made to the Py programs and modules, since the beginning.

## 0.9.4 (1/25/2004 to //2004)

Removed wxd decorators in favor of new SWIG-generated docstrings.

Removed docs tabs from crust interface: * wxPython Docs * wxSTC Docs

Fixed Calltip tab refresh problem on Windows.

shell.autoCompleteAutoHide added with default of False.

Changed default namespace of Shell to __main__.__dict__, instead of an empty dictionary.

## 0.9.3 (9/25/2003 to 1/24/2004)

Fun and games with dynamic renaming. Details of any other changes were lost in the confusion. I'll try to do better in the future.

## 0.9.2 (5/3/2003 to 9/25/2003)

Changed to the new prefix-less "wx" package:

    import wx

instead of:

    from wxPython import wx

Fixed typo in `PyWrap.py`:

    if __name__ == '__main__':
        main(sys.argv)

should have been:

    if __name__ == '__main__':
        main()

Added pretty-print Display tab to Crust, based on suggestion from Jason Whitlark.

Improved `Can*` checks in `EditWindow`, since STC is too lenient, particularly when it is set to read-only but returns True for CanPaste() (seems like an STC bug to me):

    def CanCopy(self):
        """Return True if text is selected and can be copied."""
        return self.GetSelectionStart() != self.GetSelectionEnd()

    def CanCut(self):
        """Return True if text is selected and can be cut."""
        return self.CanCopy() and self.CanEdit()

    def CanEdit(self):
        """Return True if editing should succeed."""
        return not self.GetReadOnly()

    def CanPaste(self):
        """Return True if pasting should succeed."""
        return stc.StyledTextCtrl.CanPaste(self) and self.CanEdit()

## 0.9.1 (3/21/2003 to 5/2/2003)

PyCrust is dead! Long live Py!

- Renamed `PyCrust` package to `py`.
- Moved code to wxPython's CVS repository.

Fixed bug in `introspect.py` on introspecting objects occurring immediately after a secondary prompt, like this:

    >>> l = [1, 2, 3]
    >>> for n in range(3):
    ...     l.  <-- failed to popup autocomplete list

Added documentation files:

- PyManual.txt
- wxPythonManual.txt
- wxPythonPackage.txt
- wxPythonExamples.txt

Added PyAlaMode and PyAlaCarte code editors.

Major refactoring to support `editor` and `shell` from the same base.

Renamed program files:

- `PyCrustApp.py` to `PyCrust.py`
- `PyFillingApp.py` to `PyFilling.py`
- `PyShellApp.py` to `PyShell.py`
- `wrap.py` to `PyWrap.py`

Removed disabling of autocomplete for lists of 2000 items or more. The current implementation of wxSTC can now handle lists this big.

Improved handling of `sys.path` to mimic the standard Python shell.

## 0.9 (2/27/2003 to 3/20/2003)

Added fontIncrease, fontDecrease, fontDefault signals, receivers and keybindings:

    Ctrl+]            Increase font size.
    Ctrl+[            Decrease font size.
    Ctrl+=            Default font size.

Continued enhancement of the decorator capability to provide better documentation and docstrings for wxPython classes and functions.

Introduced new tabbed interface:

- Namespace
- Calltip
- Session
- Dispatcher
- wxPython Docs
- wxSTC Docs

`Filling.tree` now expands tuples as well as lists. (It should have done this all along, I just never noticed this omission before.)

Added this True/False test to all modules:

    try:
        True
    except NameError:
        True = 1==1
        False = 1==0

Added `wxd` directory with decoration classes.

## 0.8.2 (1/5/2003 to 2/26/2003)

Wrapped `sys.ps1`, `sys.ps2`, and `sys.ps3` in `str()`. (Thanks, Kieran Holland.)

Fixed minor things found by PyChecker.

Changed locals to use `__main__.__dict__` and added code to clean up the namespace, making it as close to the regular Python environment as possible. This solves the problem of pickling and unpickling instances of classes defined in the shell.

Made `shell.PasteAndRun()` a little more forgiving when it finds a ps2 prompt line with no trailing space, such when you copy code from a web page.

Improved autocomplete behavior by adding these to shell:

    self.AutoCompSetAutoHide(False)
    self.AutoCompStops(' .,;:([)]}\'"\\<>%^&+-=*/|`')

Added `decor` directory, `decorator.py`, `stcDecor.py`, and `stcConstants.py`. These all serve the purpose of adding docstrings to existing wxPython classes, in particular the `wxStyledTextCtrl`.

Added `wrap.py`, a command line utility for running a wxPython app with additional runtime-tools loaded, such as PyCrust (the only tool at this point).

Flushed the clipboard Cut/Copy operations so that selections will exist in the clipboard even after PyCrust has been closed.

Improved the suppression of docstrings for simple data types appearing in the namespace viewer.

Better handling of autocompletion with numeric types; no autocompletion when typing a dot after an integer. If the autocompletion is desired, type a space before the dot:

    func = 3 .

More Filling!!! The namespace tree is now dynamically updated.

## 0.8.1 (12/20/2002 to 12/25/2002)

Improved keyboard handling with Autocomplete active. You can now use Enter as well as Tab to select an item from the list.

Disabled autocomplete for lists of 2000 items or more. The current implementation of wxSTC can't handle lists this big.

Changed `filling` to always display docstrings for objects. This is useful for objects whose docstrings have been decorated, rather than coming directly from the source code. (Hmmm. Sounds like someone is doing some decorating. I wonder where that would be helpful? <wink>)

Fixed handling of icon. Added `images.py` file.

## 0.8 (10/29/2002 to 12/16/2002)

Added "help" to startup banner info.

Made all `wx` and `stc` imports explicit. No more `import *`.

Replaced use of the `wx` module's `true` and `false` with Python's `True` and `False`.

Changed `introspect.getRoot()` to use `tokenize` module. This does a slightly better job than the previous parsing routine and the code is clearer.

Improved handling of whitespace and empty types during introspection.

Fixed cut/copy clipboard problem under Linux. (Robin Dunn rocks!!!)

Added shell.about() which works like this:

    >>> shell.about()
    PyCrust Version: 0.8
    Shell Revision: 1.80
    Interpreter Revision: 1.15
    Python Version: 2.2.2
    wxPython Version: 2.3.3.1
    Platform: linux2

Added copy plus and paste plus to shell menu.

Moved shell menu from `shell.py` to `shellmenu.py`.

Added `sys.stdin.readlines()` support.

Added `time.sleep()` in `readline()` and `OnIdle()` event handler to free up the CPU.

## 0.7.2 (2/22/2002 to 8/27/2002)

Tweaked `getAttributeNames()` to pick up a few more attributes:

    '__bases__', '__class__', '__dict__', '__name__', 'func_closure',
    'func_code', 'func_defaults', 'func_dict', 'func_doc',
    'func_globals', 'func_name'

Added a tests directory and unit tests.

Improved support for empty types in the shell: `[]`, `()` and `{}` as far as when call tips and autocompletion are available.

Added support for the other triple string - `''''''`.

Refactored `introspect.py` to improve testability.

Improved call tips for unbound methods by leaving the "self" parameter, since unbound methods require an instance be passed.

Fixed call tip bug where a tip was displayed when a "(" was typed after an object that wasn't callable.

Fixed `getAllAttributeNames` when `str(object)` fails.

Added brace highlighting. (Thank you, Kevin Altis.)

Fixed problem displaying unicode objects in `PyFilling`.

Changed how `filling.py` checks for expandable objects. Lists are now expandable objects.

Made the key handling more robust when there is an active text selection that includes text prior to the last primary prompt. Thanks to Raul Cota for pointing this out.

Fixed wxSTC problem with brace highlighting and non-us keyboards. (Thank you for the patch, Jean-Michel Fauth.)

Added `busy = wxBusyCursor()` to key points in `shell` and `filling`.

Added `OnCloseWindow` handler to `ShellFrame` and `CrustFrame`.

Default to `SetWrapMode(1)` for shell and namespace viewer.

Added `shell.wrap()` and `shell.zoom()`.

Added autoCompleteKeys hooks for Raul Cota.

Cleaned up various little key handling bugs.

Changed input methods to get values from shell, rather than dialog boxes. Renamed `readIn` to `readline` and `readRaw` to `raw_input`.

## 0.7.1 (12/12/2001 to 2/21/2002)

Fixed `OnChar()` issues effecting European keyboards, as reported by Jean-Michel Fauth.

Fixed `introspect.py` issue with xmlrpc objects reported by Kevin Altis.

Fixed some introspect/PyFilling issues with regard to Python 2.2.

Fixed font background color as reported by Keith J. Farmer. (Thanks)

Fixed problem with call tips and autocompletion inside multiline commands as report by Kevin Altis.

Improved `OnKeyDown` handling of cut/copy/paste operations based on feedback from Syver Enstad. (Thanks)

Added a `shell.help()` method to display some help info.

Changed sort of items in the namespace viewer to case insensitive.

Changed `attributes.sort(lambda x, y: cmp(x.upper(), y.upper()))` in advance of an upcoming fix to an autocompletion matching bug in wxSTC.

Improved support for ZODB by allowing namespace drilldown into BTrees.

Added `shell.PasteAndRun()` to support pasting multiple commands into the shell from the clipboard. Ctrl+Shift+V or v.

Enter now always processes a command (or copies down a previous one.) To insert a line break, press Ctrl+Enter.

Escape key clears the current, unexecuted command.

History retrieval changed to replace current command. Added new keys to insert from history - Shift+Up and Shift+Down.

Better call tips on objects with `__call__` methods.

Improved call tip positioning calculation.

## 0.7 (10/15/2001 to 12/11/2001)

Changed how command history retrieval functions work. Added Alt-P, Alt-N as keybindings for Retrieve-Previous, Retrieve-Next.

Added full support for multi-line commands, similar to IDLE.

Changed `introspect.getAttributeNames()` to do a case insensitive sort.

Changed Cut/Copy/Paste to deal with prompts intelligently. Cut and Copy remove all prompts. Paste can handle prompted or not-prompted text.

Added `CopyWithPrompts()` method attached to Ctrl-Shift-C for those times when you really do want all the prompts left intact.

Improved handling of the shell's read-only zone.

Changed `CrustFrame.__init__` parameter spec to include all parameters allowed by a `wxFrame`.

Changed `FillingText` to be read-only.

Renamed `PyCrust.py` to `PyCrustApp.py` to eliminate package/module name conflicts that kept you from doing `from PyCrust import shell` inside files located in the `PyCrust` directory.

Renamed `PyFilling.py` to `PyFillingApp.py` and `PyShell.py` to `PyShellApp.py` to maintain consistency.

Removed the `__date__` property from all modules.

Fixed bug in `introspect.getCallTip()`, reported by Kevin Altis.

## 0.6.1 (9/19/2001 to 10/12/2001)

Changed `Shell.run()` to always position to the end of existing text, as suggested by Raul Cota.

Changed `introspect.getAllAttributeNames()` to break circular references in `object.__class__`, which occurs in Zope/ZODB extension classes.

Changed `filling.FillingTree.getChildren()` to introspect extension classes.

Fixed minor bugs in `introspect.getCallTip()` that were interfering with call tips for Zope/ZODB extension class methods.

In preparation for wxPython 2.3.2, added code to fix a font sizing problem. Versions of wxPython prior to 2.3.2 had a sizing bug on Win platform where the font was 2 points larger than what was specified.

Added a hack to `introspect.getAllAttributeNames()` to "wake up" ZODB objects that are asleep - in a "ghost" state. Otherwise it returns incomplete info.

## 0.6 (8/21/2001 to 9/12/2001)

Added `PyFilling.py` and `filling.py`.

`PyShell.py` and `PyFilling.py` can now be run standalone, as well as `PyCrust.py`.

Added `crust.py` and moved some code from `PyCrust.py` to it.

Added command history retrieval features submitted by Richie Hindle.

Changed `shell.write()` to replace line endings with OS-specific endings. Changed `shell.py` and `interpreter.py` to use `os.linesep` in strings having hardcoded line endings.

Added `shell.redirectStdin()`, `shell.redirectStdout()` and `shell.redirectStderr()` to allow the surrounding app to toggle requests that the specified `sys.std*` be redirected to the shell. These can also be run from within the shell itself, of course.

The shell now adds the current working directory "." to the search path:

    sys.path.insert(0, os.curdir)

Added support for distutils installations.

## 0.5.4 (8/17/2001 to 8/20/2001)

Changed default font size under Linux to:

    'size'   : 12,
    'lnsize' : 10,

Changed `Shell` to expect a parameter referencing an Interpreter class, rather than an intepreter instance, to facilitate subclassing of Interpreter, which effectively broke when the Editor class was eliminated.

Fixed `PyCrustAlaCarte.py`, which had been broken by previous changes.

Created `InterpreterAlaCarte` class as an example for use in the demo.

Split `PyCrust.py` into `PyCrust.py` and `PyShell.py` in anticipation of `PyFilling.py`.

## 0.5.3 (8/16/2001)

Added patch to `PyCrust.py` to fix wxPython bug:

    wxID_SELECTALL = NewId() # This *should* be defined by wxPython.

## 0.5.2 (8/14/2001 to 8/15/2001)

Shortened module names by dropping "PyCrust" as a prefix.

Changed `version` to `VERSION` in `version` module.

Added Options menu to PyCrust application.

Eliminated the Editor class (and editor module) by merging with Shell. This means that Shell "is a" wxStyledTextCtrl rather than "has a". There just wasn't enough non-gui code to justify the separation. Plus, Shell will be much easier for gui toolkits/designers to deal with now.

## 0.5.1 (8/10/2001 to 8/14/2001)

Added `introspect` module.

Moved some functionality from `PyCrustInterp` to `introspect`.

Changed `introspect.getRoot()` to no longer remove whitespace from the command. This was a remnant of a previous approach that, when left as part of the current approach, turned out to be a really bad thing.

Changed `introspect.getRoot()` to allow commands of `''`, `""`, `""""""`, `[]`, `()`, and `{}` to pass through. This allows you to type them, followed by a dot, and get autocomplete options on them.

Changed `introspect.getRoot()` to identify some situations where strings shouldn't be considered roots. For example:

    >>> import PyCrust  # To illustrate the potential problem.
    >>> len('PyCrust.py')

Typing the dot at the end of "PyCrust" in the second line above should NOT result in an autocompletion list because "PyCrust" is part of a string in this context, not a reference to the PyCrust module object. Similar reasoning applies to call tips. For example:

    >>> len('dir(')

Typing the left paren at the end of "dir" should NOT result in a call tip.

Both features now behave properly in the examples given. However, there is still the case where whitespace precedes the potential root and that is NOT handled properly. For example:

    >>> len('this is a dir(')

and:

    >>> len('This is PyCrust.py')

More code needs to be written to handle more complex situations.

Added `locals=None` parameter to `Shell.__init__()`.

Added support for magic attribute retrieval. Users can change this with:

    >>> shell.editor.autoCompleteIncludeMagic = 0

Added the ability to set filters on auto completion to exclude attributes prefixed with a single or double underscore. Users can exclude one or the other or both with:

    >>> shell.editor.autoCompleteExcludeSingle = 1
    >>> shell.editor.autoCompleteExcludeDouble = 1

## 0.5 (8/8/2001)

Mostly just a final version change before creating a release.

## 0.4 (8/4/2001 to 8/7/2001)

Changed version/revision handling.

Fixed bugs.

## 0.3 (8/2/2001 to 8/3/2001)

Removed lots of cruft.

Added lots of docstrings.

Imported to CVS repository at SourceForge.

Added call tips.

## 0.2 (7/30/2001 to 8/2/2001)

Renamed several files.

Added command autocompletion.

Added menus to PyCrust.py: File, Edit and Help.

Added sample applications: `PyCrustAlaCarte.py`, `PyCrustAlaMode.py`, and `PyCrustMinimus.py`.

## 0.1 (7/1/2001 to 7/19/2001)

Added basic syntax coloring much like Boa.

Added read-only logging much like IDLE.

Can retrieve a previous command by putting the cursor back on that line and hitting enter.

Stdin and raw_input operate properly so you can now do `help()` and `license()` without hanging.

Redefined "quit", "exit", and "close" to display a better-than-nothing response.

Home key honors the prompt.

Created SourceForge account, but nothing was posted.

## In the beginning, there was pie... (7/1/2001)

Blame it all on IDLE, Boa and PythonWin. I was using all three, got frustrated with their dissimilarities, and began to let everyone know how I felt. At the same time, Scintilla looked like an interesting tool to build a shell around. And while I didn't receive much in the way of positive feedback, let alone encouragement, I just couldn't let go of the idea of a Scintilla-based Python shell. Then the PythonCard project got to the point where they were talking about including a shell in their development environment. That was all the incentive I needed. PyCrust had to happen...