| # Grammar for Python, version 3 |
| |
| # Changes compared to version 2: |
| # The syntax of Boolean operations is changed to use more |
| # conventional priorities: or < and < not. |
| |
| # Changes compared to version 1: |
| # modules and scripts are unified; |
| # 'quit' is gone (use ^D); |
| # empty_stmt is gone, replaced by explicit NEWLINE where appropriate; |
| # 'import' and 'def' aren't special any more; |
| # added 'from' NAME option on import clause, and '*' to import all; |
| # added class definition. |
| # TO DO: |
| # replace 'dir' by something more general? |
| |
| # Start symbols for the grammar: |
| # single_input is a single interactive statement; |
| # file_input is a module or sequence of commands read from an input file; |
| # expr_input is the input for the input() function; |
| # eval_input is the input for the eval() function. |
| |
| # NB: compound_stmt in single_input is followed by extra NEWLINE! |
| single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE |
| file_input: (NEWLINE | stmt)* ENDMARKER |
| expr_input: testlist NEWLINE |
| eval_input: testlist ENDMARKER |
| |
| funcdef: 'def' NAME parameters ':' suite |
| parameters: '(' [fplist] ')' |
| fplist: fpdef (',' fpdef)* |
| fpdef: NAME | '(' fplist ')' |
| |
| stmt: simple_stmt | compound_stmt |
| simple_stmt: expr_stmt | print_stmt | pass_stmt | del_stmt | dir_stmt | flow_stmt | import_stmt |
| expr_stmt: (exprlist '=')* exprlist NEWLINE |
| # For assignments, additional restrictions enforced by the interpreter |
| print_stmt: 'print' (test ',')* [test] NEWLINE |
| del_stmt: 'del' exprlist NEWLINE |
| dir_stmt: 'dir' [expr] NEWLINE |
| pass_stmt: 'pass' NEWLINE |
| flow_stmt: break_stmt | return_stmt | raise_stmt |
| break_stmt: 'break' NEWLINE |
| return_stmt: 'return' [testlist] NEWLINE |
| raise_stmt: 'raise' expr [',' expr] NEWLINE |
| import_stmt: 'import' NAME (',' NAME)* NEWLINE | 'from' NAME 'import' ('*' | NAME (',' NAME)*) NEWLINE |
| compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | funcdef | classdef |
| if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite] |
| while_stmt: 'while' test ':' suite ['else' ':' suite] |
| for_stmt: 'for' exprlist 'in' exprlist ':' suite ['else' ':' suite] |
| try_stmt: 'try' ':' suite (except_clause ':' suite)* ['finally' ':' suite] |
| except_clause: 'except' [expr [',' expr]] |
| suite: simple_stmt | NEWLINE INDENT NEWLINE* (stmt NEWLINE*)+ DEDENT |
| |
| test: and_test ('or' and_test)* |
| and_test: not_test ('and' not_test)* |
| not_test: 'not' not_test | comparison |
| comparison: expr (comp_op expr)* |
| comp_op: '<'|'>'|'='|'>' '='|'<' '='|'<' '>'|'in'|'not' 'in'|'is'|'is' 'not' |
| expr: term (('+'|'-') term)* |
| term: factor (('*'|'/'|'%') factor)* |
| factor: ('+'|'-') factor | atom trailer* |
| atom: '(' [testlist] ')' | '[' [testlist] ']' | '{' '}' | '`' testlist '`' | NAME | NUMBER | STRING |
| trailer: '(' [exprlist] ')' | '[' subscript ']' | '.' NAME |
| subscript: expr | [expr] ':' [expr] |
| exprlist: expr (',' expr)* [','] |
| testlist: test (',' test)* [','] |
| |
| classdef: 'class' NAME parameters ['=' baselist] ':' suite |
| baselist: atom arguments (',' atom arguments)* |
| arguments: '(' [testlist] ')' |