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Diffstat (limited to 'Doc')
| -rw-r--r-- | Doc/tutorial/appendix.rst | 124 | ||||
| -rw-r--r-- | Doc/tutorial/index.rst | 1 | ||||
| -rw-r--r-- | Doc/tutorial/interpreter.rst | 113 |
3 files changed, 128 insertions, 110 deletions
diff --git a/Doc/tutorial/appendix.rst b/Doc/tutorial/appendix.rst new file mode 100644 index 0000000..8670efc --- /dev/null +++ b/Doc/tutorial/appendix.rst @@ -0,0 +1,124 @@ +.. _tut-appendix: + +******** +Appendix +******** + + +.. _tut-interac: + +Interactive Mode +================ + +.. _tut-error: + +Error Handling +-------------- + +When an error occurs, the interpreter prints an error message and a stack trace. +In interactive mode, it then returns to the primary prompt; when input came from +a file, it exits with a nonzero exit status after printing the stack trace. +(Exceptions handled by an :keyword:`except` clause in a :keyword:`try` statement +are not errors in this context.) Some errors are unconditionally fatal and +cause an exit with a nonzero exit; this applies to internal inconsistencies and +some cases of running out of memory. All error messages are written to the +standard error stream; normal output from executed commands is written to +standard output. + +Typing the interrupt character (usually Control-C or DEL) to the primary or +secondary prompt cancels the input and returns to the primary prompt. [#]_ +Typing an interrupt while a command is executing raises the +:exc:`KeyboardInterrupt` exception, which may be handled by a :keyword:`try` +statement. + + +.. _tut-scripts: + +Executable Python Scripts +------------------------- + +On BSD'ish Unix systems, Python scripts can be made directly executable, like +shell scripts, by putting the line :: + + #!/usr/bin/env python3.4 + +(assuming that the interpreter is on the user's :envvar:`PATH`) at the beginning +of the script and giving the file an executable mode. The ``#!`` must be the +first two characters of the file. On some platforms, this first line must end +with a Unix-style line ending (``'\n'``), not a Windows (``'\r\n'``) line +ending. Note that the hash, or pound, character, ``'#'``, is used to start a +comment in Python. + +The script can be given an executable mode, or permission, using the +:program:`chmod` command. + +.. code-block:: bash + + $ chmod +x myscript.py + +On Windows systems, there is no notion of an "executable mode". The Python +installer automatically associates ``.py`` files with ``python.exe`` so that +a double-click on a Python file will run it as a script. The extension can +also be ``.pyw``, in that case, the console window that normally appears is +suppressed. + + +.. _tut-startup: + +The Interactive Startup File +---------------------------- + +When you use Python interactively, it is frequently handy to have some standard +commands executed every time the interpreter is started. You can do this by +setting an environment variable named :envvar:`PYTHONSTARTUP` to the name of a +file containing your start-up commands. This is similar to the :file:`.profile` +feature of the Unix shells. + +This file is only read in interactive sessions, not when Python reads commands +from a script, and not when :file:`/dev/tty` is given as the explicit source of +commands (which otherwise behaves like an interactive session). It is executed +in the same namespace where interactive commands are executed, so that objects +that it defines or imports can be used without qualification in the interactive +session. You can also change the prompts ``sys.ps1`` and ``sys.ps2`` in this +file. + +If you want to read an additional start-up file from the current directory, you +can program this in the global start-up file using code like ``if +os.path.isfile('.pythonrc.py'): exec(open('.pythonrc.py').read())``. +If you want to use the startup file in a script, you must do this explicitly +in the script:: + + import os + filename = os.environ.get('PYTHONSTARTUP') + if filename and os.path.isfile(filename): + with open(filename) as fobj: + startup_file = fobj.read() + exec(startup_file) + + +.. _tut-customize: + +The Customization Modules +------------------------- + +Python provides two hooks to let you customize it: :mod:`sitecustomize` and +:mod:`usercustomize`. To see how it works, you need first to find the location +of your user site-packages directory. Start Python and run this code:: + + >>> import site + >>> site.getusersitepackages() + '/home/user/.local/lib/python3.4/site-packages' + +Now you can create a file named :file:`usercustomize.py` in that directory and +put anything you want in it. It will affect every invocation of Python, unless +it is started with the :option:`-s` option to disable the automatic import. + +:mod:`sitecustomize` works in the same way, but is typically created by an +administrator of the computer in the global site-packages directory, and is +imported before :mod:`usercustomize`. See the documentation of the :mod:`site` +module for more details. + + +.. rubric:: Footnotes + +.. [#] A problem with the GNU Readline package may prevent this. diff --git a/Doc/tutorial/index.rst b/Doc/tutorial/index.rst index 604cff8..df10385 100644 --- a/Doc/tutorial/index.rst +++ b/Doc/tutorial/index.rst @@ -56,3 +56,4 @@ The :ref:`glossary` is also worth going through. whatnow.rst interactive.rst floatingpoint.rst + appendix.rst diff --git a/Doc/tutorial/interpreter.rst b/Doc/tutorial/interpreter.rst index 44dc6d1..fc9f733 100644 --- a/Doc/tutorial/interpreter.rst +++ b/Doc/tutorial/interpreter.rst @@ -112,63 +112,15 @@ example, take a look at this :keyword:`if` statement:: Be careful not to fall off! +For more on interactive mode, see :ref:`tut-interac`. + + .. _tut-interp: The Interpreter and Its Environment =================================== -.. _tut-error: - -Error Handling --------------- - -When an error occurs, the interpreter prints an error message and a stack trace. -In interactive mode, it then returns to the primary prompt; when input came from -a file, it exits with a nonzero exit status after printing the stack trace. -(Exceptions handled by an :keyword:`except` clause in a :keyword:`try` statement -are not errors in this context.) Some errors are unconditionally fatal and -cause an exit with a nonzero exit; this applies to internal inconsistencies and -some cases of running out of memory. All error messages are written to the -standard error stream; normal output from executed commands is written to -standard output. - -Typing the interrupt character (usually Control-C or DEL) to the primary or -secondary prompt cancels the input and returns to the primary prompt. [#]_ -Typing an interrupt while a command is executing raises the -:exc:`KeyboardInterrupt` exception, which may be handled by a :keyword:`try` -statement. - - -.. _tut-scripts: - -Executable Python Scripts -------------------------- - -On BSD'ish Unix systems, Python scripts can be made directly executable, like -shell scripts, by putting the line :: - - #! /usr/bin/env python3.4 - -(assuming that the interpreter is on the user's :envvar:`PATH`) at the beginning -of the script and giving the file an executable mode. The ``#!`` must be the -first two characters of the file. On some platforms, this first line must end -with a Unix-style line ending (``'\n'``), not a Windows (``'\r\n'``) line -ending. Note that the hash, or pound, character, ``'#'``, is used to start a -comment in Python. - -The script can be given an executable mode, or permission, using the -:program:`chmod` command:: - - $ chmod +x myscript.py - -On Windows systems, there is no notion of an "executable mode". The Python -installer automatically associates ``.py`` files with ``python.exe`` so that -a double-click on a Python file will run it as a script. The extension can -also be ``.pyw``, in that case, the console window that normally appears is -suppressed. - - .. _tut-source-encoding: Source Code Encoding @@ -202,67 +154,8 @@ files. The special encoding comment must be in the *first or second* line within the file. -.. _tut-startup: - -The Interactive Startup File ----------------------------- - -When you use Python interactively, it is frequently handy to have some standard -commands executed every time the interpreter is started. You can do this by -setting an environment variable named :envvar:`PYTHONSTARTUP` to the name of a -file containing your start-up commands. This is similar to the :file:`.profile` -feature of the Unix shells. - -.. XXX This should probably be dumped in an appendix, since most people - don't use Python interactively in non-trivial ways. - -This file is only read in interactive sessions, not when Python reads commands -from a script, and not when :file:`/dev/tty` is given as the explicit source of -commands (which otherwise behaves like an interactive session). It is executed -in the same namespace where interactive commands are executed, so that objects -that it defines or imports can be used without qualification in the interactive -session. You can also change the prompts ``sys.ps1`` and ``sys.ps2`` in this -file. - -If you want to read an additional start-up file from the current directory, you -can program this in the global start-up file using code like ``if -os.path.isfile('.pythonrc.py'): exec(open('.pythonrc.py').read())``. -If you want to use the startup file in a script, you must do this explicitly -in the script:: - - import os - filename = os.environ.get('PYTHONSTARTUP') - if filename and os.path.isfile(filename): - exec(open(filename).read()) - - -.. _tut-customize: - -The Customization Modules -------------------------- - -Python provides two hooks to let you customize it: :mod:`sitecustomize` and -:mod:`usercustomize`. To see how it works, you need first to find the location -of your user site-packages directory. Start Python and run this code: - - >>> import site - >>> site.getusersitepackages() - '/home/user/.local/lib/python3.2/site-packages' - -Now you can create a file named :file:`usercustomize.py` in that directory and -put anything you want in it. It will affect every invocation of Python, unless -it is started with the :option:`-s` option to disable the automatic import. - -:mod:`sitecustomize` works in the same way, but is typically created by an -administrator of the computer in the global site-packages directory, and is -imported before :mod:`usercustomize`. See the documentation of the :mod:`site` -module for more details. - - .. rubric:: Footnotes .. [#] On Unix, the Python 3.x interpreter is by default not installed with the executable named ``python``, so that it does not conflict with a simultaneously installed Python 2.x executable. - -.. [#] A problem with the GNU Readline package may prevent this. |