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diff --git a/Doc/mac/using.tex b/Doc/mac/using.tex new file mode 100644 index 0000000..3e5612e --- /dev/null +++ b/Doc/mac/using.tex @@ -0,0 +1,374 @@ +\chapter{Using Python on the Macintosh \label{using}} +\sectionauthor{Bob Savage}{bobsavage@mac.com} + +Using Python on the Macintosh can seem like something completely +different than using it on a \UNIX-like or Windows system. Most of the +Python documentation, both the ``official'' documentation and +published books, describe only how Python is used on these systems, +causing confusion for the new user of MacPython. This chapter gives a +brief introduction to the specifics of using Python on a Macintosh. + + +\section{Getting and Installing MacPython \label{getting}} + +The most recent release version as well as possible newer experimental +versions are best found at the MacPython page maintained by Jack +Jansen: \url{http://www.cwi.nl/~jack/macpython.html}. + + +Please refer to the \file{README} included with your distribution for +the most up-to-date instructions. + + +\section{Entering the interactive Interpreter + \label{interpreter}} + +The interactive interpreter that you will see used in Python +documentation is started by double-clicking the +\program{PythonInterpreter} icon, which looks like a 16-ton weight +falling. You should see the version information and the +\samp{>>>~} prompt. Use it exactly as described in the standard +documentation. + + +\section{How to run a Python script} + +There are several ways to run an existing Python script; two common +ways to run a Python script are ``drag and drop'' and ``double +clicking''. Other ways include running it from within the IDE (see +Section \ref{IDE}), or launching via AppleScript. + + +\subsection{Drag and drop} + +One of the easiest ways to launch a Python script is via ``Drag and +Drop''. This is just like launching a text file in the Finder by +``dragging'' it over your word processor's icon and ``dropping'' it +there. Make sure that you use an icon referring to the +\program{PythonInterpreter}, not the \program{IDE} or \program{Idle} +icons which have different behaviour which is described below. + +Some things that might have gone wrong: + +\begin{itemize} +\item +A window flashes after dropping the script onto the +\program{PythonInterpreter}, but then disappears. Most likely this is a +configuration issue; your \program{PythonInterpreter} is setup to exit +immediately upon completion, but your script assumes that if it prints +something that text will stick around for a while. To fix this, see +section \ref{Defaults}. + +\item +After dropping the script onto the \program{PythonInterpreter}, a +window appeared which said: ``File contains \code{\e r} characters +(incorrect line endings?)''. That script probably originated on a +\UNIX{} or Windows machine. You will need to change the line endings +to the standard Mac usage. One way to do this is to open the file in +\program{BBedit} +(\url{http://www.barebones.com/products/bbedit_lite.html}) which can +easily change the line endings between Mac, DOS, and \UNIX\ styles. + +\item +When you waved the script icon over the \program{PythonInterpreter}, +the \program{PythonInterpreter} icon did not hilight. Most likely the +Creator code and document type is unset (or set incorrectly) -- this +often happens when a file originates on a non-Mac computer. See +section \ref{CreatorCode} for more details. +\end{itemize} + + +\subsection{Set Creator and Double Click \label{creator-code}} + +If the script that you want to launch has the appropriate Creator Code +and File Type you can simply double-click on the script to launch it. +To be ``double-clickable'' a file needs to be of type \samp{TEXT}, +with a creator code of \samp{Pyth}. + +Setting the creator code and filetype can be done with the IDE (see +sections \ref{IDEwrite} and \ref{IDEapplet}), with an editor with a +Python mode (\program{BBEdit}) -- see section +\ref{scripting-with-BBedit}, or with assorted other Mac utilities, but +a script (\file{fixfiletypes.py}) has been included in the MacPython +distribution, making it possible to set the proper Type and Creator +Codes with Python. + +The \file{fixfiletypes.py} script will change the file type and +creator codes for the indicated directory. To use +\file{fixfiletypes.py}: + +\begin{enumerate} +\item +Locate it in the \file{scripts} folder of the \file{Mac} folder of the +MacPython distribution. + +\item +Put all of the scripts that you want to fix in a folder with nothing +else in it. + +\item +Double-click on the \file{fixfiletypes.py} icon. + +\item +Navigate into the folder of files you want to fix, and press the +``Select current folder'' button. +\end{enumerate} + + +\section{Simulating command line arguments + \label{argv}} + +There are two ways to simulate command-line arguments with MacPython. + +\begin{enumerate} +\item via Interpreter options +\begin{itemize} % nestable? I hope so! + \item Hold the option-key down when launching your script. This will + bring up a dialog box of Python Interpreter options. + \item Click ``Set \UNIX-style command line..'' button. + \item Type the arguments into the ``Argument'' field. + \item Click ``OK'' + \item Click ``Run''. +\end{itemize} % end + +\item via drag and drop +If you save the script as an applet (see Section \ref{IDEapplet}), you +can also simulate some command-line arguments via +``Drag-and-Drop''. In this case, the names of the files that were +dropped onto the applet will be appended to \code{sys.argv}, so that +it will appear to the script as though they had been typed on a +command line. As on \UNIX\ systems, the first item in \code{sys.srgv} is +the path to the applet, and the rest are the files dropped on the +applet. +\end{enumerate} + + +\section{Creating a Python script} + +Since Python scripts are simply text files, they can be created in any +way that text files can be created, but some special tools also exist +with extra features. + + +\subsection{In an editor} + +You can create a text file with any word processing program such as +\program{MSWord} or \program{AppleWorks} but you need to make sure +that the file is saved as ``\ASCII'' or ``plain text''. + + +\subsubsection{Editors with Python modes} + +Several text editors have additional features that add functionality +when you are creating a Python script. These can include coloring +Python keywords to make your code easier to read, module browsing, or +a built-in debugger. These include \program{Alpha}, \program{Pepper}, +and \program{BBedit}, and the MacPython IDE (Section \ref{IDE}). + +%\subsubsection{Alpha} +% **NEED INFO HERE** + +\subsubsection{BBedit \label{scripting-with-BBedit}} + +If you use \program{BBEdit} to create your scripts you will want to tell it about the Python creator code so that +you can simply double click on the saved file to launch it. +\begin{itemize} + \item Launch \program{BBEdit}. + \item Select ``Preferences'' from the ``Edit'' menu. + \item Select ``File Types'' from the scrolling list. + \item click on the ``Add...'' button and navigate to + \program{PythonInterpreter} in the main directory of the + MacPython distribution; click ``open''. + \item Click on the ``Save'' button in the Preferences panel. +\end{itemize} +% Are there additional BBedit Python-specific features? I'm not aware of any. + +%\subsubsection{IDE} +%You can use the \program{Python IDE} supplied in the MacPython Distribution to create longer Python scripts +%-- see Section \ref{IDEwrite} for details. + +%\subsubsection{IDLE} +%Idle is an IDE for Python that was written in Python, using TKInter. You should be able to use it on a Mac by following +%the standard documentation, but see Section \ref{TKInter} for guidance on using TKInter with MacPython. + +%\subsubsection{Pepper} +% **NEED INFO HERE** + + +\section{The IDE\label{IDE}} + +The \program{Python IDE} (Integrated Development Environment) is a +separate application that acts as a text editor for your Python code, +a class browser, a graphical debugger, and more. + + +\subsection{Using the ``Python Interactive'' window} + +Use this window like you would the \program{PythonInterpreter}, except +that you cannot use the ``Drag and drop'' method above. Instead, +dropping a script onto the \program{Python IDE} icon will open the +file in a seperate script window (which you can then execute manually +-- see section \ref{IDEexecution}). + + +\subsection{Writing a Python Script \label{IDEwrite}} + +In addition to using the \program{Python IDE} interactively, you can +also type out a complete Python program, saving it incrementally, and +execute it or smaller selections of it. + +You can create a new script, open a previously saved script, and save +your currently open script by selecting the appropriate item in the +``File'' menu. Dropping a Python script onto the +\program{Python IDE} will open it for editting. + +If you try to open a script with the \program{Python IDE} but either +can't locate it from the ``Open'' dialog box, or you get an error +message like ``Can't open file of type ...'' see section +\ref{CreatorCode}. + +When the \program{Python IDE} saves a script, it uses the creator code +settings which are available by clicking on the small black triangle +on the top right of the document window, and selecting ``save +options''. The default is to save the file with the \program{Python +IDE} as the creator, this means that you can open the file for editing +by simply double-clicking on its icon. You might want to change this +behaviour so that it will be opened by the +\program{PythonInterpreter}, and run. To do this simply choose +``Python Interpreter'' from the ``save options''. Note that these +options are associated with the \emph{file} not the application. + + +\subsection{Executing a script from within the IDE + \label{IDEexecution}} + +You can run the script in the frontmost window of the \program{Python +IDE} by hitting the run all button. You should be aware, however that +if you use the Python convention \samp{if __name__ == "__main__":} the +script will \emph{not} be ``__main__'' by default. To get that +behaviour you must select the ``Run as __main__'' option from the +small black triangle on the top right of the document window. Note +that this option is associated with the \emph{file} not the +application. It \emph{will} stay active after a save, however; to shut +this feature off simply select it again. + + +\subsection{``Save as'' versus ``Save as Applet'' + \label{IDEapplet}} + +When you are done writing your Python script you have the option of +saving it as an ``applet'' (by selecting ``Save as applet'' from the +``File'' menu). This has a significant advantage in that you can drop +files or folders onto it, to pass them to the applet the way +command-line users would type them onto the command-line to pass them +as arguments to the script. However, you should make sure to save the +applet as a seperate file, do not overwrite the script you are +writing, because you will not be able to edit it again. + +Accessing the items passed to the applet via ``drag-and-drop'' is done +using the standard \member{sys.argv} mechanism. See the general +documentation for more +% need to link to the appropriate place in non-Mac docs + +Note that saving a script as an applet will not make it runnable on a +system without a Python installation. + +%\subsection{Debugger} +% **NEED INFO HERE** + +%\subsection{Module Browser} +% **NEED INFO HERE** + +%\subsection{Profiler} +% **NEED INFO HERE** +% end IDE + +%\subsection{The ``Scripts'' menu} +% **NEED INFO HERE** + +\section{Configuration \label{configuration}} + +The MacPython distribution comes with \program{EditPythonPrefs}, an +applet which will help you to customize the MacPython environment for +your working habits. + +\subsection{EditPythonPrefs\label{EditPythonPrefs}} + +\program{EditPythonPrefs} gives you the capability to configure Python +to behave the way you want it to. There are two ways to use +\program{EditPythonPrefs}, you can use it to set the preferences in +general, or you can drop a particular Python engine onto it to +customize only that version. The latter can be handy if, for example, +you want to have a second copy of the \program{PythonInterpreter} that +keeps the output window open on a normal exit even though you prefer +to normally not work that way. + +To change the default preferences, simply double-click on +\program{EditPythonPrefs}. To change the preferences only for one copy +of the Interpreter, drop the icon for that copy onto +\program{EditPythonPrefs}. You can also use \program{EditPythonPrefs} +in this fashion to set the preferences of the \program{Python IDE} and +any applets you create -- see Sections \ref{BuildApplet} and +\ref{IDEapplet}. + +\subsection{Adding modules to the Module Search Path + \label{search-path}} + +When executing an \keyword{import} statement, Python looks for modules +in places defined by the \member{sys.path} To edit the +\member{sys.path} on a Mac, launch \program{EditPythonPrefs}, and +enter them into the largish field at the top (one per line). + +Since MacPython defines a main Python directory, the easiest thing is +to add folders to search within the main Python directory. To add a +folder of scripts that you created called ``My Folder'' located in the +main Python Folder, enter \samp{\$(PYTHON):My Folder} onto a new line. + +To add the Desktop under OS 9 or below, add +\samp{StartupDriveName:Desktop Folder} on a new line. + +\subsection{Default startup options \label{defaults}} + +% I'm assuming that there exists some other documentation on the +% rest of the options so I only go over a couple here. + +The ``Default startup options...'' button in the +\program{EditPythonPrefs} dialog box gives you many options including +the ability to keep the ``Output'' window open after the script +terminates, and the ability to enter interactive mode after the +termination of the run script. The latter can be very helpful if you +want to examine the objects that were created during your script. + +%\section{Nifty Tools} +%There are many other tools included with the MacPython +%distribution. In addition to those discussed here, make +%sure to check the \file{Mac} directory. + +%\subsection{BuildApplet \label{BuildApplet}} +% **NEED INFO HERE** + +%\subsection{BuildApplication} +% **NEED INFO HERE** + +%\section{TKInter on the Mac \label{TKInter}} + +%TKinter is installed by default with the MacPython distribution, but +%you may need to add the \file{lib-tk} folder to the Python Path (see +%section \ref{search-path}). Also, it is important that you do not +%try to launch Tk from within the \program{Python IDE} because the two +%event loops will collide -- always run a script which uses Tkinter +%with the \program{PythonInterpreter} instead -- see section +%\ref{interpreter}. + +%\section{CGI on the Mac with Python \label{CGI}} +%**NEED INFO HERE** + +\section{Mac OS X} + +At the time of this writing Mac OS X had just been released as a +Public Beta. Efforts are under way to bring MacPython to Mac OS X. The +MacPython release \version{1.5.2c1} runs quite well within the +``Classic'' environment. A ``Carbon'' port of the MacPython code is +being prepared for release, and several people have made a command +line version available to the ``Darwin'' layer (which is accessible +via Terminal.app). |