### 导航 - [索引](../genindex.xhtml "总目录") - [模块](../py-modindex.xhtml "Python 模块索引") | - [下一页](modules.xhtml "导入模块") | - [上一页](code.xhtml "code --- Interpreter base classes") | -  - [Python](https://www.python.org/) » - zh\_CN 3.7.3 [文档](../index.xhtml) » - [Python 标准库](index.xhtml) » - [自定义 Python 解释器](custominterp.xhtml) » - $('.inline-search').show(0); | # [`codeop`](#module-codeop "codeop: Compile (possibly incomplete) Python code.") --- Compile Python code **Source code:** [Lib/codeop.py](https://github.com/python/cpython/tree/3.7/Lib/codeop.py) \[https://github.com/python/cpython/tree/3.7/Lib/codeop.py\] - - - - - - The [`codeop`](#module-codeop "codeop: Compile (possibly incomplete) Python code.") module provides utilities upon which the Python read-eval-print loop can be emulated, as is done in the [`code`](code.xhtml#module-code "code: Facilities to implement read-eval-print loops.") module. As a result, you probably don't want to use the module directly; if you want to include such a loop in your program you probably want to use the [`code`](code.xhtml#module-code "code: Facilities to implement read-eval-print loops.")module instead. There are two parts to this job: 1. Being able to tell if a line of input completes a Python statement: in short, telling whether to print '`>>>`' or '`...`' next. 2. Remembering which future statements the user has entered, so subsequent input can be compiled with these in effect. The [`codeop`](#module-codeop "codeop: Compile (possibly incomplete) Python code.") module provides a way of doing each of these things, and a way of doing them both. To do just the former: `codeop.``compile_command`(*source*, *filename="<input>"*, *symbol="single"*)Tries to compile *source*, which should be a string of Python code and return a code object if *source* is valid Python code. In that case, the filename attribute of the code object will be *filename*, which defaults to `'<input>'`. Returns `None` if *source* is *not* valid Python code, but is a prefix of valid Python code. If there is a problem with *source*, an exception will be raised. [`SyntaxError`](exceptions.xhtml#SyntaxError "SyntaxError") is raised if there is invalid Python syntax, and [`OverflowError`](exceptions.xhtml#OverflowError "OverflowError") or [`ValueError`](exceptions.xhtml#ValueError "ValueError") if there is an invalid literal. The *symbol* argument determines whether *source* is compiled as a statement (`'single'`, the default) or as an [expression](../glossary.xhtml#term-expression) (`'eval'`). Any other value will cause [`ValueError`](exceptions.xhtml#ValueError "ValueError") to be raised. 注解 It is possible (but not likely) that the parser stops parsing with a successful outcome before reaching the end of the source; in this case, trailing symbols may be ignored instead of causing an error. For example, a backslash followed by two newlines may be followed by arbitrary garbage. This will be fixed once the API for the parser is better. *class* `codeop.``Compile`Instances of this class have [`__call__()`](../reference/datamodel.xhtml#object.__call__ "object.__call__") methods identical in signature to the built-in function [`compile()`](functions.xhtml#compile "compile"), but with the difference that if the instance compiles program text containing a [`__future__`](__future__.xhtml#module-__future__ "__future__: Future statement definitions") statement, the instance 'remembers' and compiles all subsequent program texts with the statement in force. *class* `codeop.``CommandCompiler`Instances of this class have [`__call__()`](../reference/datamodel.xhtml#object.__call__ "object.__call__") methods identical in signature to [`compile_command()`](#codeop.compile_command "codeop.compile_command"); the difference is that if the instance compiles program text containing a `__future__` statement, the instance 'remembers' and compiles all subsequent program texts with the statement in force. ### 导航 - [索引](../genindex.xhtml "总目录") - [模块](../py-modindex.xhtml "Python 模块索引") | - [下一页](modules.xhtml "导入模块") | - [上一页](code.xhtml "code --- Interpreter base classes") | -  - [Python](https://www.python.org/) » - zh\_CN 3.7.3 [文档](../index.xhtml) » - [Python 标准库](index.xhtml) » - [自定义 Python 解释器](custominterp.xhtml) » - $('.inline-search').show(0); | © [版权所有](../copyright.xhtml) 2001-2019, Python Software Foundation. Python 软件基金会是一个非盈利组织。 [请捐助。](https://www.python.org/psf/donations/) 最后更新于 5月 21, 2019. [发现了问题](../bugs.xhtml)？ 使用[Sphinx](http://sphinx.pocoo.org/)1.8.4 创建。