Added docs for 'user' customization module. Renamed libuser.tex

(which had UserDict/UserList) to libuserdict.tex.
This commit is contained in:
Guido van Rossum 1997-08-30 20:02:25 +00:00
parent d7ed683a7e
commit 36764b8b0e
5 changed files with 126 additions and 3 deletions

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@ -112,7 +112,8 @@ LIBFILES = lib.tex \
libuser.tex libanydbm.tex librandom.tex libsite.tex libwhichdb.tex \
libbase64.tex libfnmatch.tex libquopri.tex libzlib.tex libsocksvr.tex \
libmailbox.tex libcommands.tex libcmath.tex libni.tex libgzip.tex \
libpprint.tex libcode.tex libmimify.tex libre.tex libmacic.tex
libpprint.tex libcode.tex libmimify.tex libre.tex libmacic.tex \
libuserdict.tex
# Library document
lib.dvi: $(LIBFILES)

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@ -77,7 +77,7 @@ to Python and how to embed it in other applications.
\input{libpython} % Python Services
\input{libsys}
\input{libtypes2} % types is already taken :-(
\input{libuser}
\input{libuserdict}
\input{liboperator}
\input{libtraceback}
\input{libpickle}
@ -90,6 +90,7 @@ to Python and how to embed it in other applications.
\input{libpprint}
\input{libcode}
\input{libsite}
\input{libuser}
\input{libbltin} % really __builtin__
\input{libmain} % really __main__

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@ -77,7 +77,7 @@ to Python and how to embed it in other applications.
\input{libpython} % Python Services
\input{libsys}
\input{libtypes2} % types is already taken :-(
\input{libuser}
\input{libuserdict}
\input{liboperator}
\input{libtraceback}
\input{libpickle}
@ -90,6 +90,7 @@ to Python and how to embed it in other applications.
\input{libpprint}
\input{libcode}
\input{libsite}
\input{libuser}
\input{libbltin} % really __builtin__
\input{libmain} % really __main__

60
Doc/lib/libuser.tex Normal file
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@ -0,0 +1,60 @@
\section{Standard Module \sectcode{user}}
\label{module-user}
\stmodindex{user}
\kwindex{.pythonrc.py}
As a policy, Python doesn't run user-specified code on startup of
Python programs. (Only interactive sessions execute the script
specified in the \code{PYTHONPATH} environment variable if it exists).
However, some programs or sites may find it convenient to allow users
to have a standard customization file, which gets run when a program
requests it. This module implements such a mechanism. A program
that wishes to use the mechanism must execute the statement
\bcode\begin{verbatim}
import user
\end{verbatim}\ecode
The user module looks for a file \file{.pythonrc.py} in the user's
home directory and if it can be opened, exececutes it (using
\code{execfile()}) in its own (i.e. the module \code{user}'s) global
namespace. Errors during this phase are not caught; that's up to the
program that imports the user module, if it wishes. The home
directory is assumed to be named by the \code{HOME} environment
variable; if this is not set, the current directory is used.
The user's \file{.pythonrc.py} could conceivably test for
\code{sys.version} if it wishes to do different things depending on
the Python version.
A warning to users: be very conservative in what you place in your
\file{.pythonrc.py} file. Since you don't know which programs will
use it, changing the behavior of standard modules or functions is
generally not a good idea.
A suggestion for programmers who wish to use this mechanism: a simple
way to let users specify options for your package is to have them
define variables in their \var{.pythonrc.py} file that you test in
your module. For example, a module \code{spam} that has a verbosity
level can look for a variable \code{user.spam_verbose}, as follows:
\bcode\begin{verbatim}
import user
try:
verbose = user.spam_verbose # user's verbosity preference
except AttributeError:
verbose = 0 # default verbosity
\end{verbatim}\ecode
Programs with extensive customization needs are better off reading a
program-specific customization file.
Programs with security or privacy concerns should \emph{not} import
this module; a user can easily break into a a program by placing
arbitrary code in the \file{.pythonrc.py} file.
Modules for general use should \emph{not} import this module; it may
interfere with the operation of the importing program.
For a site-wide customization mechanism, see module \code{site}.

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Doc/libuser.tex Normal file
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@ -0,0 +1,60 @@
\section{Standard Module \sectcode{user}}
\label{module-user}
\stmodindex{user}
\kwindex{.pythonrc.py}
As a policy, Python doesn't run user-specified code on startup of
Python programs. (Only interactive sessions execute the script
specified in the \code{PYTHONPATH} environment variable if it exists).
However, some programs or sites may find it convenient to allow users
to have a standard customization file, which gets run when a program
requests it. This module implements such a mechanism. A program
that wishes to use the mechanism must execute the statement
\bcode\begin{verbatim}
import user
\end{verbatim}\ecode
The user module looks for a file \file{.pythonrc.py} in the user's
home directory and if it can be opened, exececutes it (using
\code{execfile()}) in its own (i.e. the module \code{user}'s) global
namespace. Errors during this phase are not caught; that's up to the
program that imports the user module, if it wishes. The home
directory is assumed to be named by the \code{HOME} environment
variable; if this is not set, the current directory is used.
The user's \file{.pythonrc.py} could conceivably test for
\code{sys.version} if it wishes to do different things depending on
the Python version.
A warning to users: be very conservative in what you place in your
\file{.pythonrc.py} file. Since you don't know which programs will
use it, changing the behavior of standard modules or functions is
generally not a good idea.
A suggestion for programmers who wish to use this mechanism: a simple
way to let users specify options for your package is to have them
define variables in their \var{.pythonrc.py} file that you test in
your module. For example, a module \code{spam} that has a verbosity
level can look for a variable \code{user.spam_verbose}, as follows:
\bcode\begin{verbatim}
import user
try:
verbose = user.spam_verbose # user's verbosity preference
except AttributeError:
verbose = 0 # default verbosity
\end{verbatim}\ecode
Programs with extensive customization needs are better off reading a
program-specific customization file.
Programs with security or privacy concerns should \emph{not} import
this module; a user can easily break into a a program by placing
arbitrary code in the \file{.pythonrc.py} file.
Modules for general use should \emph{not} import this module; it may
interfere with the operation of the importing program.
For a site-wide customization mechanism, see module \code{site}.