1
# Grammar for 2to3. This grammar supports Python 2.x and 3.x.
3
# Note: Changing the grammar specified in this file will most likely
4
# require corresponding changes in the parser module
5
# (../Modules/parsermodule.c). If you can't make the changes to
6
# that module yourself, please co-ordinate the required changes
7
# with someone who can; ask around on python-dev for help. Fred
8
# Drake <fdrake@acm.org> will probably be listening there.
10
# NOTE WELL: You should also follow all the steps listed in PEP 306,
11
# "How to Change Python's Grammar"
13
# Commands for Kees Blom's railroad program
17
#diagram:token NEWLINE
18
#diagram:token ENDMARKER
20
#diagram:output\input python.bla
22
#diagram:output\textwidth 20.04cm\oddsidemargin 0.0cm\evensidemargin 0.0cm
25
# Start symbols for the grammar:
26
# file_input is a module or sequence of commands read from an input file;
27
# single_input is a single interactive statement;
28
# eval_input is the input for the eval() and input() functions.
29
# NB: compound_stmt in single_input is followed by extra NEWLINE!
30
file_input: (NEWLINE | stmt)* ENDMARKER
31
single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
32
eval_input: testlist NEWLINE* ENDMARKER
34
decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
35
decorators: decorator+
36
decorated: decorators (classdef | funcdef)
37
funcdef: 'def' NAME parameters ['->' test] ':' suite
38
parameters: '(' [typedargslist] ')'
39
typedargslist: ((tfpdef ['=' test] ',')*
40
('*' [tname] (',' tname ['=' test])* [',' '**' tname] | '**' tname)
41
| tfpdef ['=' test] (',' tfpdef ['=' test])* [','])
42
tname: NAME [':' test]
43
tfpdef: tname | '(' tfplist ')'
44
tfplist: tfpdef (',' tfpdef)* [',']
45
varargslist: ((vfpdef ['=' test] ',')*
46
('*' [vname] (',' vname ['=' test])* [',' '**' vname] | '**' vname)
47
| vfpdef ['=' test] (',' vfpdef ['=' test])* [','])
49
vfpdef: vname | '(' vfplist ')'
50
vfplist: vfpdef (',' vfpdef)* [',']
52
stmt: simple_stmt | compound_stmt
53
simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
54
small_stmt: (expr_stmt | print_stmt | del_stmt | pass_stmt | flow_stmt |
55
import_stmt | global_stmt | exec_stmt | assert_stmt)
56
expr_stmt: testlist_star_expr (augassign (yield_expr|testlist) |
57
('=' (yield_expr|testlist_star_expr))*)
58
testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
59
augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
60
'<<=' | '>>=' | '**=' | '//=')
61
# For normal assignments, additional restrictions enforced by the interpreter
62
print_stmt: 'print' ( [ test (',' test)* [','] ] |
63
'>>' test [ (',' test)+ [','] ] )
64
del_stmt: 'del' exprlist
66
flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
68
continue_stmt: 'continue'
69
return_stmt: 'return' [testlist]
70
yield_stmt: yield_expr
71
raise_stmt: 'raise' [test ['from' test | ',' test [',' test]]]
72
import_stmt: import_name | import_from
73
import_name: 'import' dotted_as_names
74
import_from: ('from' ('.'* dotted_name | '.'+)
75
'import' ('*' | '(' import_as_names ')' | import_as_names))
76
import_as_name: NAME ['as' NAME]
77
dotted_as_name: dotted_name ['as' NAME]
78
import_as_names: import_as_name (',' import_as_name)* [',']
79
dotted_as_names: dotted_as_name (',' dotted_as_name)*
80
dotted_name: NAME ('.' NAME)*
81
global_stmt: ('global' | 'nonlocal') NAME (',' NAME)*
82
exec_stmt: 'exec' expr ['in' test [',' test]]
83
assert_stmt: 'assert' test [',' test]
85
compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated
86
if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
87
while_stmt: 'while' test ':' suite ['else' ':' suite]
88
for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
89
try_stmt: ('try' ':' suite
90
((except_clause ':' suite)+
92
['finally' ':' suite] |
94
with_stmt: 'with' with_item (',' with_item)* ':' suite
95
with_item: test ['as' expr]
97
# NB compile.c makes sure that the default except clause is last
98
except_clause: 'except' [test [(',' | 'as') test]]
99
suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
101
# Backward compatibility cruft to support:
102
# [ x for x in lambda: True, lambda: False if x() ]
103
# even while also allowing:
104
# lambda x: 5 if x else 2
105
# (But not a mix of the two)
106
testlist_safe: old_test [(',' old_test)+ [',']]
107
old_test: or_test | old_lambdef
108
old_lambdef: 'lambda' [varargslist] ':' old_test
110
test: or_test ['if' or_test 'else' test] | lambdef
111
or_test: and_test ('or' and_test)*
112
and_test: not_test ('and' not_test)*
113
not_test: 'not' not_test | comparison
114
comparison: expr (comp_op expr)*
115
comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
117
expr: xor_expr ('|' xor_expr)*
118
xor_expr: and_expr ('^' and_expr)*
119
and_expr: shift_expr ('&' shift_expr)*
120
shift_expr: arith_expr (('<<'|'>>') arith_expr)*
121
arith_expr: term (('+'|'-') term)*
122
term: factor (('*'|'@'|'/'|'%'|'//') factor)*
123
factor: ('+'|'-'|'~') factor | power
124
power: atom trailer* ['**' factor]
125
atom: ('(' [yield_expr|testlist_gexp] ')' |
126
'[' [listmaker] ']' |
127
'{' [dictsetmaker] '}' |
129
NAME | NUMBER | STRING+ | '.' '.' '.')
130
listmaker: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
131
testlist_gexp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
132
lambdef: 'lambda' [varargslist] ':' test
133
trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
134
subscriptlist: subscript (',' subscript)* [',']
135
subscript: test | [test] ':' [test] [sliceop]
137
exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
138
testlist: test (',' test)* [',']
139
dictsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
140
(test (comp_for | (',' test)* [','])) )
142
classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
144
arglist: (argument ',')* (argument [',']
145
|'*' test (',' argument)* [',' '**' test]
147
argument: test [comp_for] | test '=' test # Really [keyword '='] test
149
comp_iter: comp_for | comp_if
150
comp_for: 'for' exprlist 'in' testlist_safe [comp_iter]
151
comp_if: 'if' old_test [comp_iter]
153
testlist1: test (',' test)*
155
# not used in grammar, but may appear in "node" passed from Parser to Compiler
158
yield_expr: 'yield' [yield_arg]
159
yield_arg: 'from' test | testlist
1
# Grammar for 2to3. This grammar supports Python 2.x and 3.x.
3
# Note: Changing the grammar specified in this file will most likely
4
# require corresponding changes in the parser module
5
# (../Modules/parsermodule.c). If you can't make the changes to
6
# that module yourself, please co-ordinate the required changes
7
# with someone who can; ask around on python-dev for help. Fred
8
# Drake <fdrake@acm.org> will probably be listening there.
10
# NOTE WELL: You should also follow all the steps listed in PEP 306,
11
# "How to Change Python's Grammar"
13
# Commands for Kees Blom's railroad program
17
#diagram:token NEWLINE
18
#diagram:token ENDMARKER
20
#diagram:output\input python.bla
22
#diagram:output\textwidth 20.04cm\oddsidemargin 0.0cm\evensidemargin 0.0cm
25
# Start symbols for the grammar:
26
# file_input is a module or sequence of commands read from an input file;
27
# single_input is a single interactive statement;
28
# eval_input is the input for the eval() and input() functions.
29
# NB: compound_stmt in single_input is followed by extra NEWLINE!
30
file_input: (NEWLINE | stmt)* ENDMARKER
31
single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
32
eval_input: testlist NEWLINE* ENDMARKER
34
decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
35
decorators: decorator+
36
decorated: decorators (classdef | funcdef)
37
funcdef: 'def' NAME parameters ['->' test] ':' suite
38
parameters: '(' [typedargslist] ')'
39
typedargslist: ((tfpdef ['=' test] ',')*
40
('*' [tname] (',' tname ['=' test])* [',' '**' tname] | '**' tname)
41
| tfpdef ['=' test] (',' tfpdef ['=' test])* [','])
42
tname: NAME [':' test]
43
tfpdef: tname | '(' tfplist ')'
44
tfplist: tfpdef (',' tfpdef)* [',']
45
varargslist: ((vfpdef ['=' test] ',')*
46
('*' [vname] (',' vname ['=' test])* [',' '**' vname] | '**' vname)
47
| vfpdef ['=' test] (',' vfpdef ['=' test])* [','])
49
vfpdef: vname | '(' vfplist ')'
50
vfplist: vfpdef (',' vfpdef)* [',']
52
stmt: simple_stmt | compound_stmt
53
simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
54
small_stmt: (expr_stmt | print_stmt | del_stmt | pass_stmt | flow_stmt |
55
import_stmt | global_stmt | exec_stmt | assert_stmt)
56
expr_stmt: testlist_star_expr (augassign (yield_expr|testlist) |
57
('=' (yield_expr|testlist_star_expr))*)
58
testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
59
augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
60
'<<=' | '>>=' | '**=' | '//=')
61
# For normal assignments, additional restrictions enforced by the interpreter
62
print_stmt: 'print' ( [ test (',' test)* [','] ] |
63
'>>' test [ (',' test)+ [','] ] )
64
del_stmt: 'del' exprlist
66
flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
68
continue_stmt: 'continue'
69
return_stmt: 'return' [testlist]
70
yield_stmt: yield_expr
71
raise_stmt: 'raise' [test ['from' test | ',' test [',' test]]]
72
import_stmt: import_name | import_from
73
import_name: 'import' dotted_as_names
74
import_from: ('from' ('.'* dotted_name | '.'+)
75
'import' ('*' | '(' import_as_names ')' | import_as_names))
76
import_as_name: NAME ['as' NAME]
77
dotted_as_name: dotted_name ['as' NAME]
78
import_as_names: import_as_name (',' import_as_name)* [',']
79
dotted_as_names: dotted_as_name (',' dotted_as_name)*
80
dotted_name: NAME ('.' NAME)*
81
global_stmt: ('global' | 'nonlocal') NAME (',' NAME)*
82
exec_stmt: 'exec' expr ['in' test [',' test]]
83
assert_stmt: 'assert' test [',' test]
85
compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated
86
if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
87
while_stmt: 'while' test ':' suite ['else' ':' suite]
88
for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
89
try_stmt: ('try' ':' suite
90
((except_clause ':' suite)+
92
['finally' ':' suite] |
94
with_stmt: 'with' with_item (',' with_item)* ':' suite
95
with_item: test ['as' expr]
97
# NB compile.c makes sure that the default except clause is last
98
except_clause: 'except' [test [(',' | 'as') test]]
99
suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
101
# Backward compatibility cruft to support:
102
# [ x for x in lambda: True, lambda: False if x() ]
103
# even while also allowing:
104
# lambda x: 5 if x else 2
105
# (But not a mix of the two)
106
testlist_safe: old_test [(',' old_test)+ [',']]
107
old_test: or_test | old_lambdef
108
old_lambdef: 'lambda' [varargslist] ':' old_test
110
test: or_test ['if' or_test 'else' test] | lambdef
111
or_test: and_test ('or' and_test)*
112
and_test: not_test ('and' not_test)*
113
not_test: 'not' not_test | comparison
114
comparison: expr (comp_op expr)*
115
comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
117
expr: xor_expr ('|' xor_expr)*
118
xor_expr: and_expr ('^' and_expr)*
119
and_expr: shift_expr ('&' shift_expr)*
120
shift_expr: arith_expr (('<<'|'>>') arith_expr)*
121
arith_expr: term (('+'|'-') term)*
122
term: factor (('*'|'@'|'/'|'%'|'//') factor)*
123
factor: ('+'|'-'|'~') factor | power
124
power: atom trailer* ['**' factor]
125
atom: ('(' [yield_expr|testlist_gexp] ')' |
126
'[' [listmaker] ']' |
127
'{' [dictsetmaker] '}' |
129
NAME | NUMBER | STRING+ | '.' '.' '.')
130
listmaker: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
131
testlist_gexp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
132
lambdef: 'lambda' [varargslist] ':' test
133
trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
134
subscriptlist: subscript (',' subscript)* [',']
135
subscript: test | [test] ':' [test] [sliceop]
137
exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
138
testlist: test (',' test)* [',']
139
dictsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
140
(test (comp_for | (',' test)* [','])) )
142
classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
144
arglist: (argument ',')* (argument [',']
145
|'*' test (',' argument)* [',' '**' test]
147
argument: test [comp_for] | test '=' test # Really [keyword '='] test
149
comp_iter: comp_for | comp_if
150
comp_for: 'for' exprlist 'in' testlist_safe [comp_iter]
151
comp_if: 'if' old_test [comp_iter]
153
testlist1: test (',' test)*
155
# not used in grammar, but may appear in "node" passed from Parser to Compiler
158
yield_expr: 'yield' [yield_arg]
159
yield_arg: 'from' test | testlist
added
removed
python/Lib/lib2to3/Grammar.txt
