compile(source, filename, mode, flags=0, dont_inherit=False, optimize=-1)
將 source 編譯為代碼或者AST對(duì)象，編譯后的代碼或?qū)ο罂梢员缓瘮?shù) exec()弄跌、eval() 執(zhí)行甲喝。
說明
參數(shù) source，可以是普通字符串铛只、字節(jié)字符串或者是一個(gè) AST（Abstract Syntax Trees） 對(duì)象埠胖。即需要?jiǎng)討B(tài)執(zhí)行的代碼段。
參數(shù) filename淳玩，代碼文件名稱直撤，如果不是從文件讀取代碼則傳遞一些可辨認(rèn)的值。當(dāng)傳入了 source 參數(shù)時(shí)蜕着，filename 參數(shù)傳入空字符即可谋竖。
參數(shù) mode，指定編譯代碼的種類承匣，代碼的種類有三種蓖乘，分別為 'exec'、'eval'韧骗、'single'嘉抒。當(dāng) source 包含流程語(yǔ)句時(shí)，mode 應(yīng)指定為 'exec'宽闲；當(dāng) source 只包含單個(gè)表達(dá)式時(shí)众眨，mode 應(yīng)指定為 'eval'；當(dāng) source 包含交互式命令語(yǔ)句容诬，mode 則指定為 'single'娩梨。
示例
>>> cc = 'for i in range(0, 5): print(i)'
>>> com = compile(cc, '', 'exec')
>>> exec(com)
0
1
2
3
4
>>> cc = '2 + 3'
>>> com = compile(cc, '', 'eval')
>>> eval(com)
5
>>> cc = 'name = input("please input your name:")'
>>> com = compile(cc, '', 'single')
>>> exec(com)
please input your name:tim
>>> name
'tim'
>>>
The filename argument should give the file from which the code was read; pass some recognizable value if it wasn’t read from a file ('<string>'
is commonly used).
The mode argument specifies what kind of code must be compiled; it can be 'exec'
if source consists of a sequence of statements, 'eval'
if it consists of a single expression, or 'single'
if it consists of a single interactive statement (in the latter case, expression statements that evaluate to something other than None
will be printed).
The optional arguments flags and dont_inherit control which future statements (see PEP 236) affect the compilation of source. If neither is present (or both are zero) the code is compiled with those future statements that are in effect in the code that is calling compile()
.
If the flags argument is given and dont_inherit is not (or is zero) then the future statements specified by the flags argument are used in addition to those that would be used anyway. If dont_inherit is a non-zero integer then the flags argument is it – the future statements in effect around the call to compile are ignored.
Future statements are specified by bits which can be bitwise ORed together to specify multiple statements. The bitfield required to specify a given feature can be found as the compiler_flag
attribute on the _Feature
instance in the future
module.
The argument optimize specifies the optimization level of the compiler; the default value of -1
selects the optimization level of the interpreter as given by -O
options. Explicit levels are 0
(no optimization; debug
is true), 1
(asserts are removed, debug
is false) or 2
(docstrings are removed too).
This function raises SyntaxError
if the compiled source is invalid, and ValueError
if the source contains null bytes.
If you want to parse Python code into its AST representation, see ast.parse()
.
Note
When compiling a string with multi-line code in 'single'
or 'eval'
mode, input must be terminated by at least one newline character. This is to facilitate detection of incomplete and complete statements in the code
module.
