Python Language Reference
Implementation实现>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>> CPython
>> Jython
>> Python for .NET
>> IronPython
>> PyPy
Lexical Analysis词法分析>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Line Structure行结构<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>> Logical Lines
逻辑行
>> Physical Lines
物理行
>> Comments
注释
>> # line comment
>> Encoding Declarations
编码声明
>> # -*- coding: utf-8 -*-
GNU Emacs
>> # vim:fileencoding=<..>
VIM
>> BOM, byte order mark, \xef\xbb\xbf
notepad
>> Explicit Line Joining
显式行连接
>> \, backslash
>> Implicit Line Joining
隐式行连接
>> parentheses, square brackets or curly braces expression
(),[],{}表达式
>> Blank Lines
空行
>> contains only spaces, tabs, formfeeds, comments
仅包含空格,制表符,走纸,注释
>> Indentation
缩进
>> Whitespace between tokens
Other tokens<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
其他标识
>> NEWLINE, INDENT, DEDENT
>> identifiers, keywords, literals, operators, delimiters
Identifiers and Keywords<<<<<<<<<<<<<<<<<<<<
标识符和关键字
>> Lexical definition
identifier ::= (letter|"_") (letter | digit | "_")*
letter ::= lowercase | uppercase
lowercase ::= "a"..."z"
uppercase ::= "A"..."Z"
digit ::= "0"..."9"
>> Keywords
关键字
>> statement
语句关键词
break, continue
if, elif, else
for, in, while
try, catch, finally, except, raise
def, return
lambda, yield
>> attributes
global
>> definitions
class, True, False, None
>> directives
print, exec, pass, del
>> namespaces
as, with
import, from
>> primary expression
and, not, or
is
>> Reserved classes of identifiers
保留标识符
>> _*, store result of last evaluation in interactive interpreter
>> __*__, system-defined names
>> __*, class-private names
Literals<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
字面量
>> String Literals
stringliteral ::= [stringprefix](shortstring | longstring)
stringprefix ::= "r" | "u" | "ur" | "R" | "U" | "UR" | "Ur" | "uR"
| "b" | "B" | "br" | "Br" | "bR" | "BR"
shortstring ::= "'" shortstringitem* "'" | '"' shortstringitem* '"'
longstring ::= "'''" longstringitem* "'''"
| '"""' longstringitem* '"""'
shortstringitem ::= shortstringchar | escapeseq
longstringitem ::= longstringchar | escapeseq
shortstringchar ::=
longstringchar ::=
escapeseq ::= "\"
>> Concatenation
连接
>> +, """"
>> Numeric Literals
>> Integer and Long Integer Literals
longinteger ::= integer ("l" | "L")
integer ::= decimalinteger | octinteger | hexinteger | bininteger
decimalinteger ::= nonzerodigit digit* | "0"
octinteger ::= "0" ("o" | "O") octdigit+ | "0" octdigit+
hexinteger ::= "0" ("x" | "X") hexdigit+
bininteger ::= "0" ("b" | "B") bindigit+
nonzerodigit ::= "1"..."9"
octdigit ::= "0"..."7"
bindigit ::= "0" | "1"
hexdigit ::= digit | "a"..."f" | "A"..."F"
>> Floating Point Literals
floatnumber ::= pointfloat | exponentfloat
pointfloat ::= [intpart] fraction | intpart "."
exponentfloat ::= (intpart | pointfloat) exponent
intpart ::= digit+
fraction ::= "." digit+
exponent ::= ("e" | "E") ["+" | "-"] digit+
>> Imaginary Literals
imagnumber ::= (floatnumber | intpart) ("j" | "J")
Operators<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
运算符
>> arithmetic
+ - * ** / // %
>> comparion
< > <= >= == != <>
>> bitwise
<< >>
& | ^ ~
Delimiters<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
分隔符
() [] {}
@ , : . ` ;
= += -= *= /= //= %= &= |= ^= >>= <<= **=
>> special meaning with others
' " # \
>> not used
$ ?
Data Model数据模型>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>> Objects, values and types<<<<<<<<<<<<<<<<<<<
对象,值,类型
>> object has type and value
>> object has id
>> is compares objects
>> id() return object id
>> value
>> mutable
dictionaries, lists
>> immutable
numbers, strings, tuples
>> gc and close
>> Standard Type Hierarchy<<<<<<<<<<<<<<<<<<<<<
标准类型体系
>> None
None(truth value is false)
>> NotImplemented
NotImplemented
>> Ellipsis
Ellipsis(truth value is true)
>> numbers.Number
>> numbers.Integral
>> Plain integers
-2^31,2^31-1
>> Long integers
unlimited
>> Booleans
True, False
>> numbers.Real(float)
>> numbers.Complex
.real, .imag
>> Sequences<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>> len()
return number of items
>> slicing
[i:j]
>> extend slicing
[i:j:k]
>> Immutable sequences
>> Strings
8b,8b+
chr(), ord()
>> Unicode
16b,32b, sys.maxunicode
unichr(), ord()
encode(), unicode()
>> Tuples
>> Mutable sequences
>> del
>> Lists
>> Byte Arrays
bytearray()
>> Set types<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>> len()
return number of items
>> Sets
mutable set
set(), add()
>> Frozen sets
frozenset()
>> Mappings<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>> del
>> len()
>> Dictionaries
mutable
>> Callable types<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>> UDF
>> func_doc|__doc__
doc_string|None
Writable
>> func_name|__name__
name_string
Writable
>> __module__
module_name|None
Writable
>> func_defaults
argument_tuple|None
Writable
>> func_code
func_body_string
Writable
>> func_globals
global_var_dic
Read-only
>> func_dict
namespace
Writable
>> func_closure
var_cells|None
Read-only
>> UDM, User-defined methods
>> Read-only attributes
>> im_self, im_func, im_class
>> __doc__, __name__, __module__
>> Generator Functions
>> yield, next()
>> Build-in Functions
>> len(), math.sin()
>> Special read-only attributes
__doc__, __name__, __module__, __self__
>> Built-in Methods
>> list.append()
>> Read-only attribute
__self__
>> Class Types
__new__(), __init__()
>> Classic Classes
__init__()
>> Class Instances
>> __call__()
x.__call__(args) = x(args)
>> Modules<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>> import
>> Read-only attributes
>> __dict__
m.x = m.__dic__["x"]
>> Prefefined Attributes(writable)
__name__, __doc__, __file__
>> Classes<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
__dict__, __name__, __module__, __bases__, __doc__
>> Class instances<<<<<<<<<<<<<<<<<<<<<<<<<<<
__getattr__(), __setattr__(), __delattr__()
__dict__, __class__
>> Files<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>> open
open(), os.popen(), os.fdopen(), makefile()
>> sys.stdin, sys.stdout, sys.stderr
>> Interneal types<<<<<<<<<<<<<<<<<<<<<<<<<<<
>> Code objects
>> bytecode
>> co_name, __co_argcount, co_nlocals, co_varnames,
co_cellvars, co_freevars, co_code, co_consts, co_names,
co_filenames, co_firstlineno, co_lnotab, co_stacksize
co_flags
>> *arguments, **keywords
>> Frame objects
>> Read-only attributes
f_back, f_code, f_locals, f_globals, f_builtins, f_restricted
>> Writable attributes
f_trace, f_exc_type, f_exc_value, f_exc_traceback, f_lineno
>> Traceback objects
sys.exc_traceback, sys.exc_info()
tb_next, tb_frame, tb_lineno, tb_lasti
>> Slice objects
slice(), [i:j], [i:j:k]
start, stop, step
slice.indices(self, length)
>> Static methods objects
staticmethod()
>> Class method objects
classmethod()
New-Style and Classic Classes>>>>>>>>>>>>>>>>>>>>
Special method names特殊方法名称>>>>>>>>>>>>>>>>>>>>>>>
Basic customization<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>> object.__new__(cls[,...])
>> object.__init__(self[,...])
>> object.__del__(self)
>> object.__repr__(self)
>> object.__str__(self)
>> object.__lt__(self, other)
>> object.__le__(self, other)
>> object.__eq__(self, other)
>> object.__ne__(self, other)
>> object.__gt__(self, other)
>> object.__ge__(self, other)
>> object.__cmp__(self, other)
>> object.__rcmp__(self, other)
>> object.__hash__(self)
>> object.__nonzero__(self)
>> object.__unicode__(self)
Customizing attribute access自定义属性访问<<<<<<<<<<<<
>> object.__getattr__(self, name)
>> object.__setattr__(self, name, value)
>> object.__delattr__(self, name)
>> more for new-style classes
>> object.__getattribute__(self, name)
>> implementing descriptors
>> object.__get__(self, instance, owner)
>> object.__set__(self, instance, value)
>> object.__delete__(self, instance)
>> invoking descriptors
>> Direct Call
x.__get__(a)
>> Instance Binding
type(a).__dict__['x'].__get__(a. type(a))
>> Class Binding
A.__dict__['x'],__get__(None, A)
>> Super Binding
A.__dict__['m'].__get__(obj, obj.__class__)
>> __slots__
Customizing class creation自定义类创建<<<<<<<<<<<<<<<
>> __metaclass__
Customizaing instance and subclass checks<<<<<<
自定义实例和子类检查
>> class.__instancecheck__(self, instance)
>> class.__subclasscheck__(self, instance)
Emulating callable objects<<<<<<<<<<<<<<<<<<<<<
>> object.__call__(self[,args...])
Emulating container types<<<<<<<<<<<<<<<<<<<<<<
>> mappings
keys(), values(), items(), has_key(), get(), clear()
setdefault(), iterkeys(), itervalues(), iteritems()
pop(), popitem(), copy(), update()
>> UserDict.DictMixin
__getitem__(), __setitem__(), __delitem__(), keys()
>> mutable sequences
append(), count(), index(), extend(), insert(), pop(), remove(), reverse(), sort()
>> sequences
__add__(), __radd__(), __iadd__(), __mul__(), __rmul__(), __imul__()
>> mappings and sequences
__constains__()
>> object.__len__(self)
>> object.__getitem__(self, key)
>> object.__setitem__(self, key, value)
>> object.__delitem__(self, key)
>> object.__iter__(self)
>> object.__reversed__(self)
>> object.__contains__(self, item)
Additional methods for emulation of sequence types<<<<<<<
>> object.__getslice__(self, i, j)
>> object.__setslice__(self, i, j, sequence)
>> object.__delslice__(self, i, j)
Emulating numeric types<<<<<<<<<<<<<<<<<<<<<<<<
>> object.__add__(self, other)
>> object.__sub__(self, other)
>> object.__mul__(self, other)
>> object.__floordiv__(self, other)
>> object.__mod__(self, other)
>> object.__divmod__(self, other)
>> object.__pow__(self, other[,module])
>> object.__lshift__(self, other)
>> object.__rshift__(self, other)
>> object.__and__(self, other)
>> object.__xor__(self, other)
>> object.__or__(self, other)
>> object.__div__(self, other)
>> object.__truediv__(self, other)
>> object.__radd__(self, other)
>> object.__rsub__(self, other)
>> object.__rmul__(self, other)¶
>> object.__rdiv__(self, other)
>> object.__rtruediv__(self, other)
>> object.__rfloordiv__(self, other)
>> object.__rmod__(self, other)
>> object.__rdivmod__(self, other)
>> object.__rpow__(self, other)
>> object.__rlshift__(self, other)
>> object.__rrshift__(self, other)
>> object.__rand__(self, other)
>> object.__rxor__(self, other)
>> object.__ror__(self, other)
>> object.__iadd__(self, other)
>> object.__isub__(self, other)
>> object.__imul__(self, other)
>> object.__idiv__(self, other)
>> object.__itruediv__(self, other)
>> object.__ifloordiv__(self, other)
>> object.__imod__(self, other)¶
>> object.__ipow__(self, other[, modulo])
>> object.__ilshift__(self, other)
>> object.__irshift__(self, other)
>> object.__iand__(self, other)
>> object.__ixor__(self, other)
>> object.__ior__(self, other)
>> object.__neg__(self)
>> object.__pos__(self)¶
>> object.__abs__(self)
>> object.__invert__(self)
>> object.__complex__(self)¶
>> object.__int__(self)
>> object.__long__(self)
>> object.__float__(self)
>> object.__oct__(self)
>> object.__hex__(self)
>> object.__index__(self)
>> object.__coerce__(self, other)
Coercion rules<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
With statement context managers<<<<<<<<<<<<<<<<
>> object.__enter__(self)
>> object.__exit__(self, exc_type, exc_value, traceback)
Execution Model执行模型>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Naming and binding<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>> Names
>> block
execfile(), eval(), exec, input()
>> execution frame
>> scope
Exceptions<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>> try..except
>> raise
>> finally
Expressions表达式>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
name ::= othername
Arithmetic conversions<<<<<<<<<<<<<<<<<<<<<<<<<
Atoms<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
atom ::= identifier | literal | enclosure
enclosure ::= parenth_form | list_display
| generator_expression | dict_display | set_display
| string_conversion | yield_atom
>> identifers
>> literals
literal ::= stringliteral | integer | longinteger
| floatnumber | imagnumber
>> parenthesized forms
>> parenth_form ::= "(" [expression_list] ")"
>> list displays
list_display ::= "[" [expression_list | list_comprehension] "]"
list_comprehension ::= expression list_for
list_for ::= "for" target_list "in" old_expression_list [list_iter]
old_expression_list ::= old_expression [("," old_expression)+ [","]]
old_expression ::= or_test | old_lambda_form
list_iter ::= list_for | list_if
list_if ::= "if" old_expression [list_iter]
>> displays for sets and dictionaries
comprehension ::= expression comp_for
comp_for ::= "for" target_list "in" or_test [comp_iter]
comp_iter ::= comp_for | comp_if
comp_if ::= "if" expression_nocond [comp_iter]
>> generator expressions
generator_expression ::= "(" expression comp_for ")"
>> dictionary displays
dict_display ::= "{" [key_datum_list | dict_comprehension] "}"
key_datum_list ::= key_datum ("," key_datum)* [","]
key_datum ::= expression ":" expression
dict_comprehension ::= expression ":" expression comp_for
>> set displays
set_display ::= "{" (expression_list | comprehension) "}"
>> string conversions
string_conversion ::= "`" expression_list "`"
>> yield expressions
yield_atom ::= "(" yield_expression ")"
yield_expression ::= "yield" [expression_list]
>> generator-iterator methods
>> generator.next()
>> generator.send(value)
>> generator.throw(type[,value[,traceback]])
>> generator.close()
Primaries<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
primary ::= atom | attributeref | subscription | slicing | call
>> attribute references
attributeref ::= primary "." identifier
>> subscriptions
subscription ::= primary "[" expression_list "]"
>> slicings
slicing ::= simple_slicing | extended_slicing
simple_slicing ::= primary "[" short_slice "]"
extended_slicing ::= primary "[" slice_list "]"
slice_list ::= slice_item ("," slice_item)* [","]
slice_item ::= expression | proper_slice | ellipsis
proper_slice ::= short_slice | long_slice
short_slice ::= [lower_bound] ":" [upper_bound]
long_slice ::= short_slice ":" [stride]
lower_bound ::= expression
upper_bound ::= expression
stride ::= expression
ellipsis ::= "..."
>> Calls
call ::= primary "(" [argument_list [","]
| expression genexpr_for] ")"
argument_list ::= positional_arguments ["," keyword_arguments]
["," "*" expression] ["," keyword_arguments]
["," "**" expression]
| keyword_arguments ["," "*" expression]
["," "**" expression]
| "*" expression ["," "*" expression] ["," "**" expression]
| "**" expression
positional_arguments ::= expression ("," expression)*
keyword_arguments ::= keyword_item ("," keyword_item)*
keyword_item ::= identifier "=" expression
>> power operator
power ::= primary ["**" u_expr]
>> unary arithmetic and bitwise operations
u_expr ::= power | "-" u_expr | "+" u_expr | "~" u_expr
>> binary arithmetic operations
m_expr ::= u_expr | m_expr "*" u_expr | m_expr "//" u_expr | m_expr "/" u_expr
| m_expr "%" u_expr
a_expr ::= m_expr | a_expr "+" m_expr | a_expr "-" m_expr
>> shifting operations
shift_expr ::= a_expr | shift_expr ( "<<" | ">>" ) a_expr
>> binary bitwise operations
and_expr ::= shift_expr | and_expr "&" shift_expr
xor_expr ::= and_expr | xor_expr "^" and_expr
or_expr ::= xor_expr | or_expr "|" xor_expr
>> comparisons
comparison ::= or_expr ( comp_operator or_expr )*
comp_operator ::= "<" | ">" | "==" | ">=" | "<=" | "<>" | "!="
| "is" ["not"] | ["not"] "in"
>> boolean operations
or_test ::= and_test | or_test "or" and_test
and_test ::= not_test | and_test "and" not_test
not_test ::= comparison | "not" not_test
>> conditional expressions
conditional_expression ::= or_test ["if" or_test "else" expression]
expression ::= conditional_expression | lambda_form
>> lambdas
lambda_form ::= "lambda" [parameter_list]: expression
old_lambda_form ::= "lambda" [parameter_list]: old_expression
>> expression lists
expression_list ::= expression ( "," expression )* [","]
>> evaluation order
expr1, expr2, expr3, expr4
(expr1, expr2, expr3, expr4)
{expr1: expr2, expr3: expr4}
expr1 + expr2 * (expr3 - expr4)
expr1(expr2, expr3, *expr4, **expr5)
expr3, expr4 = expr1, expr2
Simple statements简单语句>>>>>>>>>>>>>>>>>>>>>>>>>>>>
simple_stmt ::= expression_stmt
| assert_stmt
| assignment_stmt
| augmented_assignment_stmt
| pass_stmt
| del_stmt
| print_stmt
| return_stmt
| yield_stmt
| raise_stmt
| break_stmt
| continue_stmt
| import_stmt
| global_stmt
| exec_stmt
expression statements<<<<<<<<<<<<<<<<<<<<<<<<<<
expression_stmt ::= expression_list
assignment statements<<<<<<<<<<<<<<<<<<<<<<<<<<
assignment_stmt ::= (target_list "=")+ (expression_list | yield_expression)
target_list ::= target ("," target)* [","]
target ::= identifier
| "(" target_list ")"
| "[" target_list "]"
| attributeref
| subscription
| slicing
>> augmented assignment statements
augmented_assignment_stmt ::= augtarget augop (expression_list | yield_expression)
augtarget ::= identifier | attributeref | subscription | slicing
augop ::= "+=" | "-=" | "*=" | "/=" | "//=" | "%=" | "**="
| ">>=" | "<<=" | "&=" | "^=" | "|="
assert statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
assert_stmt ::= "assert" expression ["," expression]
pass statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
pass_stmt ::= "pass"
del statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
del_stmt ::= "del" target_list
print statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
print_stmt ::= "print" ([expression ("," expression)* [","]]
| ">>" expression [("," expression)+ [","]])
return statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
return_stmt ::= "return" [expression_list]
yield statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
yield_stmt ::= yield_expression
raise statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
raise_stmt ::= "raise" [expression ["," expression ["," expression]]]
break statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
break_stmt ::= "break"
continue statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
continue_stmt ::= "continue"
import statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
import_stmt ::= "import" module ["as" name] ( "," module ["as" name] )*
| "from" relative_module "import" identifier ["as" name]
( "," identifier ["as" name] )*
| "from" relative_module "import" "(" identifier ["as" name]
( "," identifier ["as" name] )* [","] ")"
| "from" module "import" "*"
module ::= (identifier ".")* identifier
relative_module ::= "."* module | "."+
name ::= identifier
future statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
future_statement ::= "from" "__future__" "import" feature ["as" name]
("," feature ["as" name])*
| "from" "__future__" "import" "(" feature ["as" name]
("," feature ["as" name])* [","] ")"
feature ::= identifier
name ::= identifier
global statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
global_stmt ::= "global" identifier ("," identifier)*
exec statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
exec_stmt ::= "exec" or_expr ["in" expression ["," expression]]
Compound statements复合语句>>>>>>>>>>>>>>>>>>>>>>>>>>
compound_stmt ::= if_stmt
| while_stmt
| for_stmt
| try_stmt
| with_stmt
| funcdef
| classdef
| decorated
suite ::= stmt_list NEWLINE | NEWLINE INDENT statement+ DEDENT
statement ::= stmt_list NEWLINE | compound_stmt
stmt_list ::= simple_stmt (";" simple_stmt)* [";"]
if statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
if_stmt ::= "if" expression ":" suite
( "elif" expression ":" suite )*
["else" ":" suite]
while statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
while_stmt ::= "while" expression ":" suite
["else" ":" suite]
for statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
for_stmt ::= "for" target_list "in" expression_list ":" suite
["else" ":" suite]
try statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
try_stmt ::= try1_stmt | try2_stmt
try1_stmt ::= "try" ":" suite
("except" [expression [("as" | ",") target]] ":" suite)+
["else" ":" suite]
["finally" ":" suite]
try2_stmt ::= "try" ":" suite
"finally" ":" suite
with statement<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
with_stmt ::= "with" with_item ("," with_item)* ":" suite
with_item ::= expression ["as" target]
function definitions<<<<<<<<<<<<<<<<<<<<<<<<<<<
decorated ::= decorators (classdef | funcdef)
decorators ::= decorator+
decorator ::= "@" dotted_name ["(" [argument_list [","]] ")"] NEWLINE
funcdef ::= "def" funcname "(" [parameter_list] ")" ":" suite
dotted_name ::= identifier ("." identifier)*
parameter_list ::= (defparameter ",")*
( "*" identifier [, "**" identifier]
| "**" identifier
| defparameter [","] )
defparameter ::= parameter ["=" expression]
sublist ::= parameter ("," parameter)* [","]
parameter ::= identifier | "(" sublist ")"
funcname ::= identifier
class definitions<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
classdef ::= "class" classname [inheritance] ":" suite
inheritance ::= "(" [expression_list] ")"
classname ::= identifier
Top-level components顶层组件>>>>>>>>>>>>>>>>>>>>>>>>>
complete python programs<<<<<<<<<<<<<<<<<<<<<<<
>> sys
>> __builtin__
>> __main__
File Input<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
file_input ::= (NEWLINE | statement)*
Interactive Input<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
interactive_input ::= [stmt_list] NEWLINE | compound_stmt NEWLINE
Expression Input<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
eval_input ::= expression_list NEWLINE*
input_input ::= expression_list NEWLINE
