diff options
Diffstat (limited to 'Doc')
| -rw-r--r-- | Doc/lib/libdis.tex | 4 | ||||
| -rw-r--r-- | Doc/lib/libfuncs.tex | 2 | ||||
| -rw-r--r-- | Doc/lib/libstdtypes.tex | 2 | ||||
| -rw-r--r-- | Doc/tut/tut.tex | 99 |
4 files changed, 54 insertions, 53 deletions
diff --git a/Doc/lib/libdis.tex b/Doc/lib/libdis.tex index 9d709ac..f31c9f4 100644 --- a/Doc/lib/libdis.tex +++ b/Doc/lib/libdis.tex @@ -480,9 +480,9 @@ in \code{cmp_op[\var{opname}]}. \begin{opcodedesc}{IMPORT_NAME}{namei} Imports the module \code{co_names[\var{namei}]}. The module object is -pushed onto the stack. The current name space is not affected: for a +pushed onto the stack. The current namespace is not affected: for a proper import statement, a subsequent \code{STORE_FAST} instruction -modifies the name space. +modifies the namespace. \end{opcodedesc} \begin{opcodedesc}{IMPORT_FROM}{namei} diff --git a/Doc/lib/libfuncs.tex b/Doc/lib/libfuncs.tex index e6203f6..cb5acde 100644 --- a/Doc/lib/libfuncs.tex +++ b/Doc/lib/libfuncs.tex @@ -227,7 +227,7 @@ class instances are callable if they have a \method{__call__()} method. The arguments are a file name and two optional dictionaries. The file is parsed and evaluated as a sequence of Python statements (similarly to a module) using the \var{globals} and \var{locals} - dictionaries as global and local name space. If the \var{locals} + dictionaries as global and local namespace. If the \var{locals} dictionary is omitted it defaults to the \var{globals} dictionary. If both dictionaries are omitted, the expression is executed in the environment where \function{execfile()} is called. The return value is diff --git a/Doc/lib/libstdtypes.tex b/Doc/lib/libstdtypes.tex index d36cdb0..b638fa3 100644 --- a/Doc/lib/libstdtypes.tex +++ b/Doc/lib/libstdtypes.tex @@ -888,7 +888,7 @@ different object types. The implementation adds two special read-only attributes: \code{\var{f}.func_code} is a function's \dfn{code object}\obindex{code} (see below) and \code{\var{f}.func_globals} is -the dictionary used as the function's global name space (this is the +the dictionary used as the function's global namespace (this is the same as \code{\var{m}.__dict__} where \var{m} is the module in which the function \var{f} was defined). diff --git a/Doc/tut/tut.tex b/Doc/tut/tut.tex index c5a9294..0378ba4 100644 --- a/Doc/tut/tut.tex +++ b/Doc/tut/tut.tex @@ -317,7 +317,7 @@ commands. This is similar to the \file{.profile} feature of the 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 name space where +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 \code{sys.ps1} and \code{sys.ps2} in @@ -3236,24 +3236,24 @@ Pascal. Before introducing classes, I first have to tell you something about Python's scope rules. Class definitions play some neat tricks with -name spaces, and you need to know how scopes and name spaces work to +namespaces, and you need to know how scopes and namespaces work to fully understand what's going on. Incidentally, knowledge about this subject is useful for any advanced Python programmer. Let's begin with some definitions. -A \emph{name space} is a mapping from names to objects. Most name -spaces are currently implemented as Python dictionaries, but that's -normally not noticeable in any way (except for performance), and it -may change in the future. Examples of name spaces are: the set of -built-in names (functions such as \function{abs()}, and built-in exception -names); the global names in a module; and the local names in a -function invocation. In a sense the set of attributes of an object -also form a name space. The important thing to know about name -spaces is that there is absolutely no relation between names in -different name spaces; for instance, two different modules may both -define a function ``maximize'' without confusion --- users of the -modules must prefix it with the module name. +A \emph{namespace} is a mapping from names to objects. Most +namespaces are currently implemented as Python dictionaries, but +that's normally not noticeable in any way (except for performance), +and it may change in the future. Examples of namespaces are: the set +of built-in names (functions such as \function{abs()}, and built-in +exception names); the global names in a module; and the local names in +a function invocation. In a sense the set of attributes of an object +also form a namespace. The important thing to know about namespaces +is that there is absolutely no relation between names in different +namespaces; for instance, two different modules may both define a +function ``maximize'' without confusion --- users of the modules must +prefix it with the module name. By the way, I use the word \emph{attribute} for any name following a dot --- for example, in the expression \code{z.real}, \code{real} is @@ -3262,13 +3262,13 @@ names in modules are attribute references: in the expression \code{modname.funcname}, \code{modname} is a module object and \code{funcname} is an attribute of it. In this case there happens to be a straightforward mapping between the module's attributes and the -global names defined in the module: they share the same name -space!\footnote{ +global names defined in the module: they share the same namespace! +\footnote{ Except for one thing. Module objects have a secret read-only - attribute called \code{__dict__} which returns the dictionary - used to implement the module's name space; the name - \code{__dict__} is an attribute but not a global name. - Obviously, using this violates the abstraction of name space + attribute called \member{__dict__} which returns the dictionary + used to implement the module's namespace; the name + \member{__dict__} is an attribute but not a global name. + Obviously, using this violates the abstraction of namespace implementation, and should be restricted to things like post-mortem debuggers. } @@ -3280,54 +3280,54 @@ also be deleted with the \keyword{del} statement, e.g. \samp{del modname.the_answer}. Name spaces are created at different moments and have different -lifetimes. The name space containing the built-in names is created +lifetimes. The namespace containing the built-in names is created when the Python interpreter starts up, and is never deleted. The -global name space for a module is created when the module definition -is read in; normally, module name spaces also last until the +global namespace for a module is created when the module definition +is read in; normally, module namespaces also last until the interpreter quits. The statements executed by the top-level invocation of the interpreter, either read from a script file or interactively, are considered part of a module called -\module{__main__}, so they have their own global name space. (The +\module{__main__}, so they have their own global namespace. (The built-in names actually also live in a module; this is called \module{__builtin__}.) -The local name space for a function is created when the function is +The local namespace for a function is created when the function is called, and deleted when the function returns or raises an exception that is not handled within the function. (Actually, forgetting would be a better way to describe what actually happens.) Of course, -recursive invocations each have their own local name space. +recursive invocations each have their own local namespace. -A \emph{scope} is a textual region of a Python program where a name space -is directly accessible. ``Directly accessible'' here means that an -unqualified reference to a name attempts to find the name in the name -space. +A \emph{scope} is a textual region of a Python program where a +namespace is directly accessible. ``Directly accessible'' here means +that an unqualified reference to a name attempts to find the name in +the namespace. Although scopes are determined statically, they are used dynamically. At any time during execution, exactly three nested scopes are in use -(i.e., exactly three name spaces are directly accessible): the +(i.e., exactly three namespaces are directly accessible): the innermost scope, which is searched first, contains the local names, the middle scope, searched next, contains the current module's global -names, and the outermost scope (searched last) is the name space +names, and the outermost scope (searched last) is the namespace containing built-in names. Usually, the local scope references the local names of the (textually) current function. Outside of functions, the local scope references -the same name space as the global scope: the module's name space. -Class definitions place yet another name space in the local scope. +the same namespace as the global scope: the module's namespace. +Class definitions place yet another namespace in the local scope. It is important to realize that scopes are determined textually: the -global scope of a function defined in a module is that module's name -space, no matter from where or by what alias the function is called. -On the other hand, the actual search for names is done dynamically, at -run time --- however, the language definition is evolving towards -static name resolution, at ``compile'' time, so don't rely on dynamic -name resolution! (In fact, local variables are already determined -statically.) +global scope of a function defined in a module is that module's +namespace, no matter from where or by what alias the function is +called. On the other hand, the actual search for names is done +dynamically, at run time --- however, the language definition is +evolving towards static name resolution, at ``compile'' time, so don't +rely on dynamic name resolution! (In fact, local variables are +already determined statically.) A special quirk of Python is that assignments always go into the innermost scope. Assignments do not copy data --- they just bind names to objects. The same is true for deletions: the statement -\samp{del x} removes the binding of \code{x} from the name space +\samp{del x} removes the binding of \code{x} from the namespace referenced by the local scope. In fact, all operations that introduce new names use the local scope: in particular, import statements and function definitions bind the module or function name in the local @@ -3366,14 +3366,14 @@ inside a class normally have a peculiar form of argument list, dictated by the calling conventions for methods --- again, this is explained later. -When a class definition is entered, a new name space is created, and +When a class definition is entered, a new namespace is created, and used as the local scope --- thus, all assignments to local variables -go into this new name space. In particular, function definitions bind +go into this new namespace. In particular, function definitions bind the name of the new function here. When a class definition is left normally (via the end), a \emph{class object} is created. This is basically a wrapper around the contents -of the name space created by the class definition; we'll learn more +of the namespace created by the class definition; we'll learn more about class objects in the next section. The original local scope (the one in effect just before the class definitions was entered) is reinstated, and the class object is bound here to the class name given @@ -3387,7 +3387,7 @@ and instantiation. \emph{Attribute references} use the standard syntax used for all attribute references in Python: \code{obj.name}. Valid attribute -names are all the names that were in the class's name space when the +names are all the names that were in the class's namespace when the class object was created. So, if the class definition looked like this: @@ -3766,9 +3766,10 @@ code that is byte-compiled together. The same restriction applies to when referencing \code{__dict__} directly. Here's an example of a class that implements its own -\code{__getattr__} and \code{__setattr__} methods and stores all -attributes in a private variable, in a way that works in Python 1.4 as -well as in previous versions: +\method{__getattr__()} and \method{__setattr__()} methods and stores +all attributes in a private variable, in a way that works in all +versions of Python, including those available before this feature was +added: \begin{verbatim} class VirtualAttributes: |