1 :mod:`codeop` --- Compile Python code 2 ===================================== 3 4 .. module:: codeop 5 :synopsis: Compile (possibly incomplete) Python code. 6 7 .. sectionauthor:: Moshe Zadka <moshez (a] zadka.site.co.il> 8 .. sectionauthor:: Michael Hudson <mwh (a] python.net> 9 10 **Source code:** :source:`Lib/codeop.py` 11 12 -------------- 13 14 The :mod:`codeop` module provides utilities upon which the Python 15 read-eval-print loop can be emulated, as is done in the :mod:`code` module. As 16 a result, you probably don't want to use the module directly; if you want to 17 include such a loop in your program you probably want to use the :mod:`code` 18 module instead. 19 20 There are two parts to this job: 21 22 #. Being able to tell if a line of input completes a Python statement: in 23 short, telling whether to print '``>>>``' or '``...``' next. 24 25 #. Remembering which future statements the user has entered, so subsequent 26 input can be compiled with these in effect. 27 28 The :mod:`codeop` module provides a way of doing each of these things, and a way 29 of doing them both. 30 31 To do just the former: 32 33 .. function:: compile_command(source, filename="<input>", symbol="single") 34 35 Tries to compile *source*, which should be a string of Python code and return a 36 code object if *source* is valid Python code. In that case, the filename 37 attribute of the code object will be *filename*, which defaults to 38 ``'<input>'``. Returns ``None`` if *source* is *not* valid Python code, but is a 39 prefix of valid Python code. 40 41 If there is a problem with *source*, an exception will be raised. 42 :exc:`SyntaxError` is raised if there is invalid Python syntax, and 43 :exc:`OverflowError` or :exc:`ValueError` if there is an invalid literal. 44 45 The *symbol* argument determines whether *source* is compiled as a statement 46 (``'single'``, the default) or as an :term:`expression` (``'eval'``). Any 47 other value will cause :exc:`ValueError` to be raised. 48 49 .. note:: 50 51 It is possible (but not likely) that the parser stops parsing with a 52 successful outcome before reaching the end of the source; in this case, 53 trailing symbols may be ignored instead of causing an error. For example, 54 a backslash followed by two newlines may be followed by arbitrary garbage. 55 This will be fixed once the API for the parser is better. 56 57 58 .. class:: Compile() 59 60 Instances of this class have :meth:`__call__` methods identical in signature to 61 the built-in function :func:`compile`, but with the difference that if the 62 instance compiles program text containing a :mod:`__future__` statement, the 63 instance 'remembers' and compiles all subsequent program texts with the 64 statement in force. 65 66 67 .. class:: CommandCompiler() 68 69 Instances of this class have :meth:`__call__` methods identical in signature to 70 :func:`compile_command`; the difference is that if the instance compiles program 71 text containing a ``__future__`` statement, the instance 'remembers' and 72 compiles all subsequent program texts with the statement in force. 73
