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Kirill Smelkov
cpython
Commits
e0ebb4dd
Commit
e0ebb4dd
authored
Mar 03, 1998
by
Fred Drake
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Logical markup.
parent
15182382
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View file @
e0ebb4dd
...
...
@@ -8,33 +8,33 @@ are always available. They are listed here in alphabetical order.
\setindexsubitem
{
(built-in function)
}
\begin{funcdesc}
{__
import
__}{
name
\optional
{
, globals
\optional
{
, locals
\optional
{
, fromlist
}}}}
This function is invoked by the
\
code
{
import
}
statement. It
This function is invoked by the
\
keyword
{
import
}
statement. It
mainly exists so that you can replace it with another
function that has a compatible interface, in order to change the
semantics of the
\
code
{
import
}
statement. For examples of why and
how you would do this, see the standard library modules
\
cod
e
{
ni
}
,
\
code
{
ihooks
}
and
\cod
e
{
rexec
}
. See also the built-in module
\
cod
e
{
imp
}
, which defines some useful operations out of which you can
build your own
\
code
{__
import
__
()
}
function.
semantics of the
\
keyword
{
import
}
statement. For examples of why and
how you would do this, see the standard library modules
\
modul
e
{
ni
}
,
\
module
{
ihooks
}
and
\modul
e
{
rexec
}
. See also the built-in module
\
modul
e
{
imp
}
, which defines some useful operations out of which you can
build your own
\
function
{__
import
__
()
}
function.
\stindex
{
import
}
\refstmodindex
{
ni
}
\refstmodindex
{
ihooks
}
\refstmodindex
{
rexec
}
\refbimodindex
{
imp
}
For example, the statement
\code
{
import
}
\code
{
spam
}
results in the
For example, the statement
`
\code
{
import
}
\code
{
spam
}
'
results in the
following call:
\code
{__
import
__
('spam',
}
\code
{
globals(),
}
\code
{
locals(), [])
}
;
the statement
\code
{
from
}
\code
{
spam.ham import
}
\code
{
eggs
}
results
in
\code
{__
import
__
('spam.ham',
}
\code
{
globals(),
}
\code
{
locals(),
}
\code
{
['eggs'])
}
.
Note that even though
\code
{
locals()
}
and
\code
{
['eggs']
}
are passed
in as arguments, the
\
code
{__
import
__
()
}
function does not set the
in as arguments, the
\
function
{__
import
__
()
}
function does not set the
local variable named
\code
{
eggs
}
; this is done by subsequent code that
is generated for the import statement. (In fact, the standard
implementation does not use its
\var
{
locals
}
argument at all, and uses
its
\var
{
globals
}
only to determine the package context of the
\
code
{
import
}
statement.)
\
keyword
{
import
}
statement.)
When the
\var
{
name
}
variable is of the form
\code
{
package.module
}
,
normally, the top-level package (the name up till the first dot) is
...
...
@@ -42,8 +42,8 @@ returned, \emph{not} the module named by \var{name}. However, when a
non-empty
\var
{
fromlist
}
argument is given, the module named by
\var
{
name
}
is returned. This is done for compatibility with the
bytecode generated for the different kinds of import statement; when
using
\
code
{
import spam.ham.eggs
}
, the top-level package
\code
{
spam
}
must be placed in the importing namespace, but when using
\
code
{
from
using
\
samp
{
import spam.ham.eggs
}
, the top-level package
\code
{
spam
}
must be placed in the importing namespace, but when using
\
samp
{
from
spam.ham import eggs
}
, the
\code
{
spam.ham
}
subpackage must be used to
find the
\code
{
eggs
}
variable.
\end{funcdesc}
...
...
@@ -72,13 +72,13 @@ Return true if the \var{object} argument appears callable, false if
not. If this returns true, it is still possible that a call fails,
but if it is false, calling
\var
{
object
}
will never succeed. Note
that classes are callable (calling a class returns a new instance);
class instances are callable if they have a
n attribute
\code
{__
call
__}
.
class instances are callable if they have a
\method
{__
call
__
()
}
method
.
\end{funcdesc}
\begin{funcdesc}
{
chr
}{
i
}
Return a string of one character whose
\ASCII
{}
code is the integer
\var
{
i
}
, e.g.,
\code
{
chr(97)
}
returns the string
\code
{
'a'
}
. This is the
inverse of
\
code
{
ord()
}
. The argument must be in the range [0..255],
inverse of
\
function
{
ord()
}
. The argument must be in the range [0..255],
inclusive.
\end{funcdesc}
...
...
@@ -97,8 +97,8 @@ class instances are callable if they have an attribute \code{__call__}.
\begin{funcdesc}
{
compile
}{
string
\,
filename
\,
kind
}
Compile the
\var
{
string
}
into a code object. Code objects can be
executed by an
\
code
{
exec
}
statement or evaluated by a call to
\
code
{
eval()
}
. The
\var
{
filename
}
argument should
executed by an
\
keyword
{
exec
}
statement or evaluated by a call to
\
function
{
eval()
}
. The
\var
{
filename
}
argument should
give the file from which the code was read; pass e.g.
\code
{
'<string>'
}
if it wasn't read from a file. The
\var
{
kind
}
argument specifies
what kind of code must be compiled; it can be
\code
{
'exec'
}
if
...
...
@@ -113,12 +113,12 @@ class instances are callable if they have an attribute \code{__call__}.
Create a complex number with the value
\var
{
real
}
+
\var
{
imag
}
*j.
Each argument may be any numeric type (including complex).
If
\var
{
imag
}
is omitted, it defaults to zero and the function
serves as a numeric conversion function like
\
code
{
int
}
,
\code
{
long
}
and
\code
{
float
}
.
serves as a numeric conversion function like
\
function
{
int()
}
,
\function
{
long()
}
and
\function
{
float()
}
.
\end{funcdesc}
\begin{funcdesc}
{
delattr
}{
object
\,
name
}
This is a relative of
\
code
{
setattr
}
. The arguments are an
This is a relative of
\
function
{
setattr()
}
. The arguments are an
object and a string. The string must be the name
of one of the object's attributes. The function deletes
the named attribute, provided the object allows it. For example,
...
...
@@ -130,7 +130,7 @@ class instances are callable if they have an attribute \code{__call__}.
Without arguments, return the list of names in the current local
symbol table. With an argument, attempts to return a list of valid
attribute for that object. This information is gleaned from the
object's
\
code
{__
dict
__}
,
\code
{__
methods
__}
and
\code
{__
members
__}
object's
\
member
{__
dict
__}
,
\member
{__
methods
__}
and
\member
{__
members
__}
attributes, if defined. The list is not necessarily complete; e.g.,
for classes, attributes defined in base classes are not included,
and for class instances, methods are not included.
...
...
@@ -163,7 +163,7 @@ class instances are callable if they have an attribute \code{__call__}.
\var
{
globals
}
and
\var
{
locals
}
dictionaries as global and local name
space. 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
\
code
{
eval
}
is
expression is executed in the environment where
\
keyword
{
eval
}
is
called. The return value is the result of the evaluated expression.
Syntax errors are reported as exceptions. Example:
...
...
@@ -173,28 +173,28 @@ class instances are callable if they have an attribute \code{__call__}.
2
>>>
\end{verbatim}
%
This function can also be used to execute arbitrary code objects
(e.g.
\
created by
\
code
{
compile()
}
). In this case pass a code
(e.g.
\
created by
\
function
{
compile()
}
). In this case pass a code
object instead of a string. The code object must have been compiled
passing
\code
{
'eval'
}
to the
\var
{
kind
}
argument.
Hints: dynamic execution of statements is supported by the
\
code
{
exec
}
statement. Execution of statements from a file is
supported by the
\
code
{
execfile()
}
function. The
\code
{
globals()
}
and
\code
{
locals()
}
functions returns the current global and local
dictionary, respectively, which may be useful
to pass around for use by
\code
{
eval()
}
or
\code
{
execfile()
}
.
\
keyword
{
exec
}
statement. Execution of statements from a file is
supported by the
\
function
{
execfile()
}
function. The
\function
{
globals()
}
and
\function
{
locals()
}
functions returns the
current global and local dictionary, respectively, which may be
useful to pass around for use by
\function
{
eval()
}
or
\function
{
execfile()
}
.
\end{funcdesc}
\begin{funcdesc}
{
execfile
}{
file
\optional
{
\,
globals
\optional
{
\,
locals
}}}
This function is similar to the
\
code
{
exec
}
statement, but parses a file instead of a string. It is
different from the
\code
{
import
}
statement in that it does not use
the module administration --- it reads the file unconditionally and
does not create a new module.
\footnote
{
It is used relatively rar
ely
so does not warrant being made into a statement.
}
\
keyword
{
exec
}
statement, but parses a file instead of a string. It
is different from the
\keyword
{
import
}
statement in that it does not
use the module administration --- it reads the file unconditionally
and does not create a new module.
\footnote
{
It is used relativ
ely
rarely
so does not warrant being made into a statement.
}
The arguments are a file name and two optional dictionaries. The
file is parsed and evaluated as a sequence of Python statements
...
...
@@ -202,7 +202,7 @@ class instances are callable if they have an attribute \code{__call__}.
dictionaries as global and local name space. 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
\
code
{
execfile()
}
is called. The return value is
environment where
\
function
{
execfile()
}
is called. The return value is
\code
{
None
}
.
\end{funcdesc}
...
...
@@ -228,10 +228,9 @@ removed.
\begin{funcdesc}
{
getattr
}{
object
\,
name
}
The arguments are an object and a string. The string must be the
name
of one of the object's attributes. The result is the value of that
attribute. For example,
\code
{
getattr(
\var
{
x
}
, '
\var
{
foobar
}
')
}
is equivalent to
\code
{
\var
{
x
}
.
\var
{
foobar
}}
.
name of one of the object's attributes. The result is the value of
that attribute. For example,
\code
{
getattr(
\var
{
x
}
,
'
\var
{
foobar
}
')
}
is equivalent to
\code
{
\var
{
x
}
.
\var
{
foobar
}}
.
\end{funcdesc}
\begin{funcdesc}
{
globals
}{}
...
...
@@ -244,8 +243,8 @@ module from which it is called).
\begin{funcdesc}
{
hasattr
}{
object
\,
name
}
The arguments are an object and a string. The result is 1 if the
string is the name of one of the object's attributes, 0 if not.
(This is implemented by calling
\code
{
getattr(
object, name)
}
and
seeing whether it raises an exception or not.)
(This is implemented by calling
\code
{
getattr(
\var
{
object
}
,
\var
{
name
}
)
}
and
seeing whether it raises an exception or not.)
\end{funcdesc}
\begin{funcdesc}
{
hash
}{
object
}
...
...
@@ -263,21 +262,21 @@ module from which it is called).
\code
{
'0xffffffff'
}
. When evaluated on a machine with the same
word size, this literal is evaluated as -1; at a different word
size, it may turn up as a large positive number or raise an
\
code
{
OverflowError
}
exception.
\
exception
{
OverflowError
}
exception.
\end{funcdesc}
\begin{funcdesc}
{
id
}{
object
}
Return the `identity' of an object. This is an integer which is
guaranteed to be unique and constant for this object during its
lifetime. (Two objects whose lifetimes are disjunct may have the
same
id() value.) (Implementation note: this is the address of
the
object.)
same
\function
{
id()
}
value.) (Implementation note: this is
the
address of the
object.)
\end{funcdesc}
\begin{funcdesc}
{
input
}{
\optional
{
prompt
}}
Almost equivalent to
\code
{
eval(raw
_
input(
\var
{
prompt
}
))
}
. Like
\
code
{
raw
_
input()
}
, the
\var
{
prompt
}
argument is optional, and the
\
cod
e
{
readline
}
module is used when loaded. The difference
\
function
{
raw
_
input()
}
, the
\var
{
prompt
}
argument is optional, and the
\
modul
e
{
readline
}
module is used when loaded. The difference
is that a long input expression may be broken over multiple lines using
the backslash convention.
\end{funcdesc}
...
...
@@ -314,13 +313,14 @@ Also return true if \var{class} is a type object and \var{object} is
an object of that type. If
\var
{
object
}
is not a class instance or a
object of the given type, the function always returns false. If
\var
{
class
}
is neither a class object nor a type object, a
\
code
{
TypeError
}
exception is raised.
\
exception
{
TypeError
}
exception is raised.
\end{funcdesc}
\begin{funcdesc}
{
issubclass
}{
class1, class2
}
Return true if
\var
{
class1
}
is a subclass (direct or indirect) of
\var
{
class2
}
. A class is considered a subclass of itself. If either
argument is not a class object, a
\code
{
TypeError
}
exception is raised.
argument is not a class object, a
\exception
{
TypeError
}
exception is
raised.
\end{funcdesc}
\begin{funcdesc}
{
len
}{
s
}
...
...
@@ -352,7 +352,7 @@ desired effect.
long integer or a floating point number, and a long integer with
the same value is returned. Conversion of floating
point numbers to integers is defined by the C semantics;
see the description of
\
code
{
int()
}
.
see the description of
\
function
{
int()
}
.
\end{funcdesc}
\begin{funcdesc}
{
map
}{
function
\,
list
\,
...
}
...
...
@@ -362,7 +362,7 @@ of the results. If additional \var{list} arguments are passed,
the items of all lists in parallel; if a list is shorter than another
it is assumed to be extended with
\code
{
None
}
items. If
\var
{
function
}
is
\code
{
None
}
, the identity function is assumed; if
there are multiple list arguments,
\
code
{
map
}
returns a list
there are multiple list arguments,
\
function
{
map()
}
returns a list
consisting of tuples containing the corresponding items from all lists
(i.e. a kind of transpose operation). The
\var
{
list
}
arguments may be
any kind of sequence; the result is always a list.
...
...
@@ -385,13 +385,13 @@ any kind of sequence; the result is always a list.
\code
{
'037777777777'
}
. When evaluated on a machine with the same
word size, this literal is evaluated as -1; at a different word
size, it may turn up as a large positive number or raise an
\
code
{
OverflowError
}
exception.
\
exception
{
OverflowError
}
exception.
\end{funcdesc}
\begin{funcdesc}
{
open
}{
filename
\optional
{
\,
mode
\optional
{
\,
bufsize
}}}
Return a new file object (described earlier under Built-in Types).
The first two arguments are the same as for
\code
{
stdio
}
's
\c
ode
{
fopen()
}
:
\var
{
filename
}
is the file name to be opened,
\c
function
{
fopen()
}
:
\var
{
filename
}
is the file name to be opened,
\var
{
mode
}
indicates how the file is to be opened:
\code
{
'r'
}
for
reading,
\code
{
'w'
}
for writing (truncating an existing file), and
\code
{
'a'
}
opens it for appending (which on
\emph
{
some
}
\UNIX
{}
...
...
@@ -401,8 +401,8 @@ any kind of sequence; the result is always a list.
\code
{
'a+'
}
open the file for updating, provided the underlying
\code
{
stdio
}
library understands this. On systems that differentiate
between binary and text files,
\code
{
'b'
}
appended to the mode opens
the file in binary mode. If the file cannot be opened,
\code
{
IOError
}
is raised.
the file in binary mode. If the file cannot be opened,
\exception
{
IOError
}
is raised.
If
\var
{
mode
}
is omitted, it defaults to
\code
{
'r'
}
.
The optional
\var
{
bufsize
}
argument specifies the file's desired
buffer size: 0 means unbuffered, 1 means line buffered, any other
...
...
@@ -411,8 +411,8 @@ negative \var{bufsize} means to use the system default, which is
usually line buffered for for tty devices and fully buffered for other
files.
%
\footnote
{
Specifying a buffer size currently has no effect on systems
that don't have
\c
ode
{
setvbuf()
}
. The interface to specify the buffer
size is not done using a method that calls
\c
ode
{
setvbuf()
}
, because
that don't have
\c
function
{
setvbuf()
}
. The interface to specify the buffer
size is not done using a method that calls
\c
function
{
setvbuf()
}
, because
that may dump core when called after any I/O has been performed, and
there's no reliable way to determine whether this is the case.
}
\end{funcdesc}
...
...
@@ -420,7 +420,7 @@ there's no reliable way to determine whether this is the case.}
\begin{funcdesc}
{
ord
}{
c
}
Return the
\ASCII
{}
value of a string of one character. E.g.,
\code
{
ord('a')
}
returns the integer
\code
{
97
}
. This is the inverse of
\
code
{
chr()
}
.
\
function
{
chr()
}
.
\end{funcdesc}
\begin{funcdesc}
{
pow
}{
x
\,
y
\optional
{
\,
z
}}
...
...
@@ -437,7 +437,7 @@ there's no reliable way to determine whether this is the case.}
\begin{funcdesc}
{
range
}{
\optional
{
start
\,
}
stop
\optional
{
\,
step
}}
This is a versatile function to create lists containing arithmetic
progressions. It is most often used in
\
code
{
for
}
loops. The
progressions. It is most often used in
\
keyword
{
for
}
loops. The
arguments must be plain integers. If the
\var
{
step
}
argument is
omitted, it defaults to
\code
{
1
}
. If the
\var
{
start
}
argument is
omitted, it defaults to
\code
{
0
}
. The full form returns a list of
...
...
@@ -472,7 +472,7 @@ there's no reliable way to determine whether this is the case.}
If the
\var
{
prompt
}
argument is present, it is written to standard output
without a trailing newline. The function then reads a line from input,
converts it to a string (stripping a trailing newline), and returns that.
When
\EOF
{}
is read,
\
code
{
EOFError
}
is raised. Example:
When
\EOF
{}
is read,
\
exception
{
EOFError
}
is raised. Example:
\begin{verbatim}
>>> s = raw
_
input('--> ')
...
...
@@ -482,8 +482,8 @@ there's no reliable way to determine whether this is the case.}
>>>
\end{verbatim}
If the
\
cod
e
{
readline
}
module was loaded, then
\
code
{
raw
_
input()
}
will use it to provide elaborate
If the
\
modul
e
{
readline
}
module was loaded, then
\
function
{
raw
_
input()
}
will use it to provide elaborate
line editing and history features.
\end{funcdesc}
...
...
@@ -508,11 +508,11 @@ module object (i.e.\ the same as the \var{module} argument).
There are a number of caveats:
If a module is syntactically correct but its initialization fails, the
first
\
code
{
import
}
statement for it does not bind its name locally,
first
\
keyword
{
import
}
statement for it does not bind its name locally,
but does store a (partially initialized) module object in
\code
{
sys.modules
}
. To reload the module you must first
\
code
{
import
}
it again (this will bind the name to the partially
initialized module object) before you can
\
code
{
reload()
}
it.
\
keyword
{
import
}
it again (this will bind the name to the partially
initialized module object) before you can
\
function
{
reload()
}
it.
When a module is reloaded, its dictionary (containing the module's
global variables) is retained. Redefinitions of names will override
...
...
@@ -520,21 +520,21 @@ the old definitions, so this is generally not a problem. If the new
version of a module does not define a name that was defined by the old
version, the old definition remains. This feature can be used to the
module's advantage if it maintains a global table or cache of objects
--- with a
\
code
{
try
}
statement it can test for the table's presence
--- with a
\
keyword
{
try
}
statement it can test for the table's presence
and skip its initialization if desired.
It is legal though generally not very useful to reload built-in or
dynamically loaded modules, except for
\
code
{
sys
}
,
\code
{__
main
__}
and
\code
{__
builtin
__}
. In certain cases, however, extension modules are
not designed to be initialized more than once, and may fail in
arbitrary ways when reloaded.
If a module imports objects from another module using
\
code
{
from
}
\ldots
{}
\
code
{
import
}
\ldots
{}
, calling
\code
{
reload()
}
for the othe
r
module does not redefine the objects imported from it --- one way
around this is to re-execute the
\code
{
from
}
statement, another is to
use
\code
{
import
}
and qualified names (
\var
{
module
}
.
\var
{
name
}
)
instead.
dynamically loaded modules, except for
\
module
{
sys
}
,
\module
{__
main
__}
and
\module
{__
builtin
__}
. In certain cases, however, extension
modules are not designed to be initialized more than once, and may
fail in
arbitrary ways when reloaded.
If a module imports objects from another module using
\
keyword
{
from
}
\ldots
{}
\
keyword
{
import
}
\ldots
{}
, calling
\function
{
reload()
}
fo
r
the other module does not redefine the objects imported from it ---
one way around this is to re-execute the
\keyword
{
from
}
statement,
another is to use
\keyword
{
import
}
and qualified names
(
\var
{
module
}
.
\var
{
name
}
)
instead.
If a module instantiates instances of a class, reloading the module
that defines the class does not affect the method definitions of the
...
...
@@ -548,7 +548,7 @@ This is the same value yielded by conversions (reverse quotes).
It is sometimes useful to be able to access this operation as an
ordinary function. For many types, this function makes an attempt
to return a string that would yield an object with the same value
when passed to
\
code
{
eval()
}
.
when passed to
\
function
{
eval()
}
.
\end{funcdesc}
\begin{funcdesc}
{
round
}{
x
\,
n
}
...
...
@@ -561,7 +561,7 @@ when passed to \code{eval()}.
\end{funcdesc}
\begin{funcdesc}
{
setattr
}{
object
\,
name
\,
value
}
This is the counterpart of
\
code
{
getattr
}
. The arguments are an
This is the counterpart of
\
function
{
getattr()
}
. The arguments are an
object, a string and an arbitrary value. The string must be the name
of one of the object's attributes. The function assigns the value to
the attribute, provided the object allows it. For example,
...
...
@@ -573,7 +573,7 @@ when passed to \code{eval()}.
Return a slice object representing the set of indices specified by
\code
{
range(
\var
{
start
}
,
\var
{
stop
}
,
\var
{
step
}
)
}
. The
\var
{
start
}
and
\var
{
step
}
arguments default to None. Slice objects have
read-only data attributes
\
code
{
start
}
,
\code
{
stop
}
and
\code
{
step
}
read-only data attributes
\
member
{
start
}
,
\member
{
stop
}
and
\member
{
step
}
which merely return the argument values (or their default). They have
no other explicit functionality; however they are used by Numerical
Python and other third party extensions. Slice objects are also
...
...
@@ -585,7 +585,7 @@ generated when extended indexing syntax is used, e.g. for
Return a string containing a nicely printable representation of an
object. For strings, this returns the string itself. The difference
with
\code
{
repr(
\var
{
object
}
)
}
is that
\code
{
str(
\var
{
object
}
)
}
does not
always attempt to return a string that is acceptable to
\
code
{
eval()
}
;
always attempt to return a string that is acceptable to
\
function
{
eval()
}
;
its goal is to return a printable string.
\end{funcdesc}
...
...
@@ -599,7 +599,7 @@ returns \code{('a', 'b', 'c')} and \code{tuple([1, 2, 3])} returns
\begin{funcdesc}
{
type
}{
object
}
Return the type of an
\var
{
object
}
. The return value is a type
object. The standard module
\
cod
e
{
types
}
defines names for all
object. The standard module
\
modul
e
{
types
}
defines names for all
built-in types.
\refstmodindex
{
types
}
\obindex
{
type
}
...
...
@@ -614,7 +614,7 @@ For instance:
\begin{funcdesc}
{
vars
}{
\optional
{
object
}}
Without arguments, return a dictionary corresponding to the current
local symbol table. With a module, class or class instance object as
argument (or anything else that has a
\
code
{__
dict
__}
attribute),
argument (or anything else that has a
\
member
{__
dict
__}
attribute),
returns a dictionary corresponding to the object's symbol table.
The returned dictionary should not be modified: the effects on the
corresponding symbol table are undefined.
%
...
...
@@ -624,13 +624,13 @@ other scopes (e.g. modules) can be. This may change.}
\end{funcdesc}
\begin{funcdesc}
{
xrange
}{
\optional
{
start
\,
}
stop
\optional
{
\,
step
}}
This function is very similar to
\
code
{
range()
}
, but returns an
This function is very similar to
\
function
{
range()
}
, but returns an
``xrange object'' instead of a list. This is an opaque sequence type
which yields the same values as the corresponding list, without
actually storing them all simultaneously. The advantage of
\
code
{
xrange()
}
over
\code
{
range()
}
is minimal (since
\code
{
xrange()
}
still has to create the values when asked for them) except when a very
large range is used on a memory-starved machine (e.g. MS-DOS) or when all
of the range's elements are never used (e.g. when the loop is usually
terminated with
\code
{
break
}
).
\
function
{
xrange()
}
over
\function
{
range()
}
is minimal (since
\function
{
xrange()
}
still has to create the values when asked for
them) except when a very large range is used on a memory-starved
machine (e.g. MS-DOS) or when all of the range's elements are never
used (e.g. when the loop is usually terminated with
\keyword
{
break
}
).
\end{funcdesc}
Doc/libfuncs.tex
View file @
e0ebb4dd
...
...
@@ -8,33 +8,33 @@ are always available. They are listed here in alphabetical order.
\setindexsubitem
{
(built-in function)
}
\begin{funcdesc}
{__
import
__}{
name
\optional
{
, globals
\optional
{
, locals
\optional
{
, fromlist
}}}}
This function is invoked by the
\
code
{
import
}
statement. It
This function is invoked by the
\
keyword
{
import
}
statement. It
mainly exists so that you can replace it with another
function that has a compatible interface, in order to change the
semantics of the
\
code
{
import
}
statement. For examples of why and
how you would do this, see the standard library modules
\
cod
e
{
ni
}
,
\
code
{
ihooks
}
and
\cod
e
{
rexec
}
. See also the built-in module
\
cod
e
{
imp
}
, which defines some useful operations out of which you can
build your own
\
code
{__
import
__
()
}
function.
semantics of the
\
keyword
{
import
}
statement. For examples of why and
how you would do this, see the standard library modules
\
modul
e
{
ni
}
,
\
module
{
ihooks
}
and
\modul
e
{
rexec
}
. See also the built-in module
\
modul
e
{
imp
}
, which defines some useful operations out of which you can
build your own
\
function
{__
import
__
()
}
function.
\stindex
{
import
}
\refstmodindex
{
ni
}
\refstmodindex
{
ihooks
}
\refstmodindex
{
rexec
}
\refbimodindex
{
imp
}
For example, the statement
\code
{
import
}
\code
{
spam
}
results in the
For example, the statement
`
\code
{
import
}
\code
{
spam
}
'
results in the
following call:
\code
{__
import
__
('spam',
}
\code
{
globals(),
}
\code
{
locals(), [])
}
;
the statement
\code
{
from
}
\code
{
spam.ham import
}
\code
{
eggs
}
results
in
\code
{__
import
__
('spam.ham',
}
\code
{
globals(),
}
\code
{
locals(),
}
\code
{
['eggs'])
}
.
Note that even though
\code
{
locals()
}
and
\code
{
['eggs']
}
are passed
in as arguments, the
\
code
{__
import
__
()
}
function does not set the
in as arguments, the
\
function
{__
import
__
()
}
function does not set the
local variable named
\code
{
eggs
}
; this is done by subsequent code that
is generated for the import statement. (In fact, the standard
implementation does not use its
\var
{
locals
}
argument at all, and uses
its
\var
{
globals
}
only to determine the package context of the
\
code
{
import
}
statement.)
\
keyword
{
import
}
statement.)
When the
\var
{
name
}
variable is of the form
\code
{
package.module
}
,
normally, the top-level package (the name up till the first dot) is
...
...
@@ -42,8 +42,8 @@ returned, \emph{not} the module named by \var{name}. However, when a
non-empty
\var
{
fromlist
}
argument is given, the module named by
\var
{
name
}
is returned. This is done for compatibility with the
bytecode generated for the different kinds of import statement; when
using
\
code
{
import spam.ham.eggs
}
, the top-level package
\code
{
spam
}
must be placed in the importing namespace, but when using
\
code
{
from
using
\
samp
{
import spam.ham.eggs
}
, the top-level package
\code
{
spam
}
must be placed in the importing namespace, but when using
\
samp
{
from
spam.ham import eggs
}
, the
\code
{
spam.ham
}
subpackage must be used to
find the
\code
{
eggs
}
variable.
\end{funcdesc}
...
...
@@ -72,13 +72,13 @@ Return true if the \var{object} argument appears callable, false if
not. If this returns true, it is still possible that a call fails,
but if it is false, calling
\var
{
object
}
will never succeed. Note
that classes are callable (calling a class returns a new instance);
class instances are callable if they have a
n attribute
\code
{__
call
__}
.
class instances are callable if they have a
\method
{__
call
__
()
}
method
.
\end{funcdesc}
\begin{funcdesc}
{
chr
}{
i
}
Return a string of one character whose
\ASCII
{}
code is the integer
\var
{
i
}
, e.g.,
\code
{
chr(97)
}
returns the string
\code
{
'a'
}
. This is the
inverse of
\
code
{
ord()
}
. The argument must be in the range [0..255],
inverse of
\
function
{
ord()
}
. The argument must be in the range [0..255],
inclusive.
\end{funcdesc}
...
...
@@ -97,8 +97,8 @@ class instances are callable if they have an attribute \code{__call__}.
\begin{funcdesc}
{
compile
}{
string
\,
filename
\,
kind
}
Compile the
\var
{
string
}
into a code object. Code objects can be
executed by an
\
code
{
exec
}
statement or evaluated by a call to
\
code
{
eval()
}
. The
\var
{
filename
}
argument should
executed by an
\
keyword
{
exec
}
statement or evaluated by a call to
\
function
{
eval()
}
. The
\var
{
filename
}
argument should
give the file from which the code was read; pass e.g.
\code
{
'<string>'
}
if it wasn't read from a file. The
\var
{
kind
}
argument specifies
what kind of code must be compiled; it can be
\code
{
'exec'
}
if
...
...
@@ -113,12 +113,12 @@ class instances are callable if they have an attribute \code{__call__}.
Create a complex number with the value
\var
{
real
}
+
\var
{
imag
}
*j.
Each argument may be any numeric type (including complex).
If
\var
{
imag
}
is omitted, it defaults to zero and the function
serves as a numeric conversion function like
\
code
{
int
}
,
\code
{
long
}
and
\code
{
float
}
.
serves as a numeric conversion function like
\
function
{
int()
}
,
\function
{
long()
}
and
\function
{
float()
}
.
\end{funcdesc}
\begin{funcdesc}
{
delattr
}{
object
\,
name
}
This is a relative of
\
code
{
setattr
}
. The arguments are an
This is a relative of
\
function
{
setattr()
}
. The arguments are an
object and a string. The string must be the name
of one of the object's attributes. The function deletes
the named attribute, provided the object allows it. For example,
...
...
@@ -130,7 +130,7 @@ class instances are callable if they have an attribute \code{__call__}.
Without arguments, return the list of names in the current local
symbol table. With an argument, attempts to return a list of valid
attribute for that object. This information is gleaned from the
object's
\
code
{__
dict
__}
,
\code
{__
methods
__}
and
\code
{__
members
__}
object's
\
member
{__
dict
__}
,
\member
{__
methods
__}
and
\member
{__
members
__}
attributes, if defined. The list is not necessarily complete; e.g.,
for classes, attributes defined in base classes are not included,
and for class instances, methods are not included.
...
...
@@ -163,7 +163,7 @@ class instances are callable if they have an attribute \code{__call__}.
\var
{
globals
}
and
\var
{
locals
}
dictionaries as global and local name
space. 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
\
code
{
eval
}
is
expression is executed in the environment where
\
keyword
{
eval
}
is
called. The return value is the result of the evaluated expression.
Syntax errors are reported as exceptions. Example:
...
...
@@ -173,28 +173,28 @@ class instances are callable if they have an attribute \code{__call__}.
2
>>>
\end{verbatim}
%
This function can also be used to execute arbitrary code objects
(e.g.
\
created by
\
code
{
compile()
}
). In this case pass a code
(e.g.
\
created by
\
function
{
compile()
}
). In this case pass a code
object instead of a string. The code object must have been compiled
passing
\code
{
'eval'
}
to the
\var
{
kind
}
argument.
Hints: dynamic execution of statements is supported by the
\
code
{
exec
}
statement. Execution of statements from a file is
supported by the
\
code
{
execfile()
}
function. The
\code
{
globals()
}
and
\code
{
locals()
}
functions returns the current global and local
dictionary, respectively, which may be useful
to pass around for use by
\code
{
eval()
}
or
\code
{
execfile()
}
.
\
keyword
{
exec
}
statement. Execution of statements from a file is
supported by the
\
function
{
execfile()
}
function. The
\function
{
globals()
}
and
\function
{
locals()
}
functions returns the
current global and local dictionary, respectively, which may be
useful to pass around for use by
\function
{
eval()
}
or
\function
{
execfile()
}
.
\end{funcdesc}
\begin{funcdesc}
{
execfile
}{
file
\optional
{
\,
globals
\optional
{
\,
locals
}}}
This function is similar to the
\
code
{
exec
}
statement, but parses a file instead of a string. It is
different from the
\code
{
import
}
statement in that it does not use
the module administration --- it reads the file unconditionally and
does not create a new module.
\footnote
{
It is used relatively rar
ely
so does not warrant being made into a statement.
}
\
keyword
{
exec
}
statement, but parses a file instead of a string. It
is different from the
\keyword
{
import
}
statement in that it does not
use the module administration --- it reads the file unconditionally
and does not create a new module.
\footnote
{
It is used relativ
ely
rarely
so does not warrant being made into a statement.
}
The arguments are a file name and two optional dictionaries. The
file is parsed and evaluated as a sequence of Python statements
...
...
@@ -202,7 +202,7 @@ class instances are callable if they have an attribute \code{__call__}.
dictionaries as global and local name space. 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
\
code
{
execfile()
}
is called. The return value is
environment where
\
function
{
execfile()
}
is called. The return value is
\code
{
None
}
.
\end{funcdesc}
...
...
@@ -228,10 +228,9 @@ removed.
\begin{funcdesc}
{
getattr
}{
object
\,
name
}
The arguments are an object and a string. The string must be the
name
of one of the object's attributes. The result is the value of that
attribute. For example,
\code
{
getattr(
\var
{
x
}
, '
\var
{
foobar
}
')
}
is equivalent to
\code
{
\var
{
x
}
.
\var
{
foobar
}}
.
name of one of the object's attributes. The result is the value of
that attribute. For example,
\code
{
getattr(
\var
{
x
}
,
'
\var
{
foobar
}
')
}
is equivalent to
\code
{
\var
{
x
}
.
\var
{
foobar
}}
.
\end{funcdesc}
\begin{funcdesc}
{
globals
}{}
...
...
@@ -244,8 +243,8 @@ module from which it is called).
\begin{funcdesc}
{
hasattr
}{
object
\,
name
}
The arguments are an object and a string. The result is 1 if the
string is the name of one of the object's attributes, 0 if not.
(This is implemented by calling
\code
{
getattr(
object, name)
}
and
seeing whether it raises an exception or not.)
(This is implemented by calling
\code
{
getattr(
\var
{
object
}
,
\var
{
name
}
)
}
and
seeing whether it raises an exception or not.)
\end{funcdesc}
\begin{funcdesc}
{
hash
}{
object
}
...
...
@@ -263,21 +262,21 @@ module from which it is called).
\code
{
'0xffffffff'
}
. When evaluated on a machine with the same
word size, this literal is evaluated as -1; at a different word
size, it may turn up as a large positive number or raise an
\
code
{
OverflowError
}
exception.
\
exception
{
OverflowError
}
exception.
\end{funcdesc}
\begin{funcdesc}
{
id
}{
object
}
Return the `identity' of an object. This is an integer which is
guaranteed to be unique and constant for this object during its
lifetime. (Two objects whose lifetimes are disjunct may have the
same
id() value.) (Implementation note: this is the address of
the
object.)
same
\function
{
id()
}
value.) (Implementation note: this is
the
address of the
object.)
\end{funcdesc}
\begin{funcdesc}
{
input
}{
\optional
{
prompt
}}
Almost equivalent to
\code
{
eval(raw
_
input(
\var
{
prompt
}
))
}
. Like
\
code
{
raw
_
input()
}
, the
\var
{
prompt
}
argument is optional, and the
\
cod
e
{
readline
}
module is used when loaded. The difference
\
function
{
raw
_
input()
}
, the
\var
{
prompt
}
argument is optional, and the
\
modul
e
{
readline
}
module is used when loaded. The difference
is that a long input expression may be broken over multiple lines using
the backslash convention.
\end{funcdesc}
...
...
@@ -314,13 +313,14 @@ Also return true if \var{class} is a type object and \var{object} is
an object of that type. If
\var
{
object
}
is not a class instance or a
object of the given type, the function always returns false. If
\var
{
class
}
is neither a class object nor a type object, a
\
code
{
TypeError
}
exception is raised.
\
exception
{
TypeError
}
exception is raised.
\end{funcdesc}
\begin{funcdesc}
{
issubclass
}{
class1, class2
}
Return true if
\var
{
class1
}
is a subclass (direct or indirect) of
\var
{
class2
}
. A class is considered a subclass of itself. If either
argument is not a class object, a
\code
{
TypeError
}
exception is raised.
argument is not a class object, a
\exception
{
TypeError
}
exception is
raised.
\end{funcdesc}
\begin{funcdesc}
{
len
}{
s
}
...
...
@@ -352,7 +352,7 @@ desired effect.
long integer or a floating point number, and a long integer with
the same value is returned. Conversion of floating
point numbers to integers is defined by the C semantics;
see the description of
\
code
{
int()
}
.
see the description of
\
function
{
int()
}
.
\end{funcdesc}
\begin{funcdesc}
{
map
}{
function
\,
list
\,
...
}
...
...
@@ -362,7 +362,7 @@ of the results. If additional \var{list} arguments are passed,
the items of all lists in parallel; if a list is shorter than another
it is assumed to be extended with
\code
{
None
}
items. If
\var
{
function
}
is
\code
{
None
}
, the identity function is assumed; if
there are multiple list arguments,
\
code
{
map
}
returns a list
there are multiple list arguments,
\
function
{
map()
}
returns a list
consisting of tuples containing the corresponding items from all lists
(i.e. a kind of transpose operation). The
\var
{
list
}
arguments may be
any kind of sequence; the result is always a list.
...
...
@@ -385,13 +385,13 @@ any kind of sequence; the result is always a list.
\code
{
'037777777777'
}
. When evaluated on a machine with the same
word size, this literal is evaluated as -1; at a different word
size, it may turn up as a large positive number or raise an
\
code
{
OverflowError
}
exception.
\
exception
{
OverflowError
}
exception.
\end{funcdesc}
\begin{funcdesc}
{
open
}{
filename
\optional
{
\,
mode
\optional
{
\,
bufsize
}}}
Return a new file object (described earlier under Built-in Types).
The first two arguments are the same as for
\code
{
stdio
}
's
\c
ode
{
fopen()
}
:
\var
{
filename
}
is the file name to be opened,
\c
function
{
fopen()
}
:
\var
{
filename
}
is the file name to be opened,
\var
{
mode
}
indicates how the file is to be opened:
\code
{
'r'
}
for
reading,
\code
{
'w'
}
for writing (truncating an existing file), and
\code
{
'a'
}
opens it for appending (which on
\emph
{
some
}
\UNIX
{}
...
...
@@ -401,8 +401,8 @@ any kind of sequence; the result is always a list.
\code
{
'a+'
}
open the file for updating, provided the underlying
\code
{
stdio
}
library understands this. On systems that differentiate
between binary and text files,
\code
{
'b'
}
appended to the mode opens
the file in binary mode. If the file cannot be opened,
\code
{
IOError
}
is raised.
the file in binary mode. If the file cannot be opened,
\exception
{
IOError
}
is raised.
If
\var
{
mode
}
is omitted, it defaults to
\code
{
'r'
}
.
The optional
\var
{
bufsize
}
argument specifies the file's desired
buffer size: 0 means unbuffered, 1 means line buffered, any other
...
...
@@ -411,8 +411,8 @@ negative \var{bufsize} means to use the system default, which is
usually line buffered for for tty devices and fully buffered for other
files.
%
\footnote
{
Specifying a buffer size currently has no effect on systems
that don't have
\c
ode
{
setvbuf()
}
. The interface to specify the buffer
size is not done using a method that calls
\c
ode
{
setvbuf()
}
, because
that don't have
\c
function
{
setvbuf()
}
. The interface to specify the buffer
size is not done using a method that calls
\c
function
{
setvbuf()
}
, because
that may dump core when called after any I/O has been performed, and
there's no reliable way to determine whether this is the case.
}
\end{funcdesc}
...
...
@@ -420,7 +420,7 @@ there's no reliable way to determine whether this is the case.}
\begin{funcdesc}
{
ord
}{
c
}
Return the
\ASCII
{}
value of a string of one character. E.g.,
\code
{
ord('a')
}
returns the integer
\code
{
97
}
. This is the inverse of
\
code
{
chr()
}
.
\
function
{
chr()
}
.
\end{funcdesc}
\begin{funcdesc}
{
pow
}{
x
\,
y
\optional
{
\,
z
}}
...
...
@@ -437,7 +437,7 @@ there's no reliable way to determine whether this is the case.}
\begin{funcdesc}
{
range
}{
\optional
{
start
\,
}
stop
\optional
{
\,
step
}}
This is a versatile function to create lists containing arithmetic
progressions. It is most often used in
\
code
{
for
}
loops. The
progressions. It is most often used in
\
keyword
{
for
}
loops. The
arguments must be plain integers. If the
\var
{
step
}
argument is
omitted, it defaults to
\code
{
1
}
. If the
\var
{
start
}
argument is
omitted, it defaults to
\code
{
0
}
. The full form returns a list of
...
...
@@ -472,7 +472,7 @@ there's no reliable way to determine whether this is the case.}
If the
\var
{
prompt
}
argument is present, it is written to standard output
without a trailing newline. The function then reads a line from input,
converts it to a string (stripping a trailing newline), and returns that.
When
\EOF
{}
is read,
\
code
{
EOFError
}
is raised. Example:
When
\EOF
{}
is read,
\
exception
{
EOFError
}
is raised. Example:
\begin{verbatim}
>>> s = raw
_
input('--> ')
...
...
@@ -482,8 +482,8 @@ there's no reliable way to determine whether this is the case.}
>>>
\end{verbatim}
If the
\
cod
e
{
readline
}
module was loaded, then
\
code
{
raw
_
input()
}
will use it to provide elaborate
If the
\
modul
e
{
readline
}
module was loaded, then
\
function
{
raw
_
input()
}
will use it to provide elaborate
line editing and history features.
\end{funcdesc}
...
...
@@ -508,11 +508,11 @@ module object (i.e.\ the same as the \var{module} argument).
There are a number of caveats:
If a module is syntactically correct but its initialization fails, the
first
\
code
{
import
}
statement for it does not bind its name locally,
first
\
keyword
{
import
}
statement for it does not bind its name locally,
but does store a (partially initialized) module object in
\code
{
sys.modules
}
. To reload the module you must first
\
code
{
import
}
it again (this will bind the name to the partially
initialized module object) before you can
\
code
{
reload()
}
it.
\
keyword
{
import
}
it again (this will bind the name to the partially
initialized module object) before you can
\
function
{
reload()
}
it.
When a module is reloaded, its dictionary (containing the module's
global variables) is retained. Redefinitions of names will override
...
...
@@ -520,21 +520,21 @@ the old definitions, so this is generally not a problem. If the new
version of a module does not define a name that was defined by the old
version, the old definition remains. This feature can be used to the
module's advantage if it maintains a global table or cache of objects
--- with a
\
code
{
try
}
statement it can test for the table's presence
--- with a
\
keyword
{
try
}
statement it can test for the table's presence
and skip its initialization if desired.
It is legal though generally not very useful to reload built-in or
dynamically loaded modules, except for
\
code
{
sys
}
,
\code
{__
main
__}
and
\code
{__
builtin
__}
. In certain cases, however, extension modules are
not designed to be initialized more than once, and may fail in
arbitrary ways when reloaded.
If a module imports objects from another module using
\
code
{
from
}
\ldots
{}
\
code
{
import
}
\ldots
{}
, calling
\code
{
reload()
}
for the othe
r
module does not redefine the objects imported from it --- one way
around this is to re-execute the
\code
{
from
}
statement, another is to
use
\code
{
import
}
and qualified names (
\var
{
module
}
.
\var
{
name
}
)
instead.
dynamically loaded modules, except for
\
module
{
sys
}
,
\module
{__
main
__}
and
\module
{__
builtin
__}
. In certain cases, however, extension
modules are not designed to be initialized more than once, and may
fail in
arbitrary ways when reloaded.
If a module imports objects from another module using
\
keyword
{
from
}
\ldots
{}
\
keyword
{
import
}
\ldots
{}
, calling
\function
{
reload()
}
fo
r
the other module does not redefine the objects imported from it ---
one way around this is to re-execute the
\keyword
{
from
}
statement,
another is to use
\keyword
{
import
}
and qualified names
(
\var
{
module
}
.
\var
{
name
}
)
instead.
If a module instantiates instances of a class, reloading the module
that defines the class does not affect the method definitions of the
...
...
@@ -548,7 +548,7 @@ This is the same value yielded by conversions (reverse quotes).
It is sometimes useful to be able to access this operation as an
ordinary function. For many types, this function makes an attempt
to return a string that would yield an object with the same value
when passed to
\
code
{
eval()
}
.
when passed to
\
function
{
eval()
}
.
\end{funcdesc}
\begin{funcdesc}
{
round
}{
x
\,
n
}
...
...
@@ -561,7 +561,7 @@ when passed to \code{eval()}.
\end{funcdesc}
\begin{funcdesc}
{
setattr
}{
object
\,
name
\,
value
}
This is the counterpart of
\
code
{
getattr
}
. The arguments are an
This is the counterpart of
\
function
{
getattr()
}
. The arguments are an
object, a string and an arbitrary value. The string must be the name
of one of the object's attributes. The function assigns the value to
the attribute, provided the object allows it. For example,
...
...
@@ -573,7 +573,7 @@ when passed to \code{eval()}.
Return a slice object representing the set of indices specified by
\code
{
range(
\var
{
start
}
,
\var
{
stop
}
,
\var
{
step
}
)
}
. The
\var
{
start
}
and
\var
{
step
}
arguments default to None. Slice objects have
read-only data attributes
\
code
{
start
}
,
\code
{
stop
}
and
\code
{
step
}
read-only data attributes
\
member
{
start
}
,
\member
{
stop
}
and
\member
{
step
}
which merely return the argument values (or their default). They have
no other explicit functionality; however they are used by Numerical
Python and other third party extensions. Slice objects are also
...
...
@@ -585,7 +585,7 @@ generated when extended indexing syntax is used, e.g. for
Return a string containing a nicely printable representation of an
object. For strings, this returns the string itself. The difference
with
\code
{
repr(
\var
{
object
}
)
}
is that
\code
{
str(
\var
{
object
}
)
}
does not
always attempt to return a string that is acceptable to
\
code
{
eval()
}
;
always attempt to return a string that is acceptable to
\
function
{
eval()
}
;
its goal is to return a printable string.
\end{funcdesc}
...
...
@@ -599,7 +599,7 @@ returns \code{('a', 'b', 'c')} and \code{tuple([1, 2, 3])} returns
\begin{funcdesc}
{
type
}{
object
}
Return the type of an
\var
{
object
}
. The return value is a type
object. The standard module
\
cod
e
{
types
}
defines names for all
object. The standard module
\
modul
e
{
types
}
defines names for all
built-in types.
\refstmodindex
{
types
}
\obindex
{
type
}
...
...
@@ -614,7 +614,7 @@ For instance:
\begin{funcdesc}
{
vars
}{
\optional
{
object
}}
Without arguments, return a dictionary corresponding to the current
local symbol table. With a module, class or class instance object as
argument (or anything else that has a
\
code
{__
dict
__}
attribute),
argument (or anything else that has a
\
member
{__
dict
__}
attribute),
returns a dictionary corresponding to the object's symbol table.
The returned dictionary should not be modified: the effects on the
corresponding symbol table are undefined.
%
...
...
@@ -624,13 +624,13 @@ other scopes (e.g. modules) can be. This may change.}
\end{funcdesc}
\begin{funcdesc}
{
xrange
}{
\optional
{
start
\,
}
stop
\optional
{
\,
step
}}
This function is very similar to
\
code
{
range()
}
, but returns an
This function is very similar to
\
function
{
range()
}
, but returns an
``xrange object'' instead of a list. This is an opaque sequence type
which yields the same values as the corresponding list, without
actually storing them all simultaneously. The advantage of
\
code
{
xrange()
}
over
\code
{
range()
}
is minimal (since
\code
{
xrange()
}
still has to create the values when asked for them) except when a very
large range is used on a memory-starved machine (e.g. MS-DOS) or when all
of the range's elements are never used (e.g. when the loop is usually
terminated with
\code
{
break
}
).
\
function
{
xrange()
}
over
\function
{
range()
}
is minimal (since
\function
{
xrange()
}
still has to create the values when asked for
them) except when a very large range is used on a memory-starved
machine (e.g. MS-DOS) or when all of the range's elements are never
used (e.g. when the loop is usually terminated with
\keyword
{
break
}
).
\end{funcdesc}
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