The Very High Level Layer

The functions in this chapter will let you execute Python source code given in afile or a buffer, but they will not let you interact in a more detailed way withthe interpreter.

Several of these functions accept a start symbol from the grammar as aparameter. The available start symbols arePy_eval_input,Py_file_input, andPy_single_input. These are describedfollowing the functions which accept them as parameters.

Note also that several of these functions takeFILE* parameters. Oneparticular issue which needs to be handled carefully is that theFILEstructure for different C libraries can be different and incompatible. UnderWindows (at least), it is possible for dynamically linked extensions to actuallyuse different libraries, so care should be taken thatFILE* parametersare only passed to these functions if it is certain that they were created bythe same library that the Python runtime is using.

intPyRun_AnyFile(FILE*fp,constchar*filename)

This is a simplified interface toPyRun_AnyFileExFlags() below, leavingcloseit set to0 andflags set toNULL.

intPyRun_AnyFileFlags(FILE*fp,constchar*filename,PyCompilerFlags*flags)

This is a simplified interface toPyRun_AnyFileExFlags() below, leavingthecloseit argument set to0.

intPyRun_AnyFileEx(FILE*fp,constchar*filename,intcloseit)

This is a simplified interface toPyRun_AnyFileExFlags() below, leavingtheflags argument set toNULL.

intPyRun_AnyFileExFlags(FILE*fp,constchar*filename,intcloseit,PyCompilerFlags*flags)

Iffp refers to a file associated with an interactive device (console orterminal input or Unix pseudo-terminal), return the value ofPyRun_InteractiveLoop(), otherwise return the result ofPyRun_SimpleFile().filename is decoded from the filesystemencoding (sys.getfilesystemencoding()). Iffilename isNULL, thisfunction uses"???" as the filename.Ifcloseit is true, the file is closed beforePyRun_SimpleFileExFlags() returns.

intPyRun_SimpleString(constchar*command)

This is a simplified interface toPyRun_SimpleStringFlags() below,leaving thePyCompilerFlags* argument set toNULL.

intPyRun_SimpleStringFlags(constchar*command,PyCompilerFlags*flags)

Executes the Python source code fromcommand in the__main__ moduleaccording to theflags argument. If__main__ does not already exist, itis created. Returns0 on success or-1 if an exception was raised. Ifthere was an error, there is no way to get the exception information. For themeaning offlags, see below.

Note that if an otherwise unhandledSystemExit is raised, thisfunction will not return-1, but exit the process, as long asPyConfig.inspect is zero.

intPyRun_SimpleFile(FILE*fp,constchar*filename)

This is a simplified interface toPyRun_SimpleFileExFlags() below,leavingcloseit set to0 andflags set toNULL.

intPyRun_SimpleFileEx(FILE*fp,constchar*filename,intcloseit)

This is a simplified interface toPyRun_SimpleFileExFlags() below,leavingflags set toNULL.

intPyRun_SimpleFileExFlags(FILE*fp,constchar*filename,intcloseit,PyCompilerFlags*flags)

Similar toPyRun_SimpleStringFlags(), but the Python source code is readfromfp instead of an in-memory string.filename should be the name ofthe file, it is decoded fromfilesystem encoding and error handler.Ifcloseit is true, the file is closed beforePyRun_SimpleFileExFlags() returns.

備註

On Windows,fp should be opened as binary mode (e.g.fopen(filename,"rb")).Otherwise, Python may not handle script file with LF line ending correctly.

intPyRun_InteractiveOne(FILE*fp,constchar*filename)

This is a simplified interface toPyRun_InteractiveOneFlags() below,leavingflags set toNULL.

intPyRun_InteractiveOneFlags(FILE*fp,constchar*filename,PyCompilerFlags*flags)

Read and execute a single statement from a file associated with aninteractive device according to theflags argument. The user will beprompted usingsys.ps1 andsys.ps2.filename is decoded from thefilesystem encoding and error handler.

Returns0 when the input wasexecuted successfully,-1 if there was an exception, or an error codefrom theerrcode.h include file distributed as part of Python ifthere was a parse error. (Note thaterrcode.h is not included byPython.h, so must be included specifically if needed.)

intPyRun_InteractiveLoop(FILE*fp,constchar*filename)

This is a simplified interface toPyRun_InteractiveLoopFlags() below,leavingflags set toNULL.

intPyRun_InteractiveLoopFlags(FILE*fp,constchar*filename,PyCompilerFlags*flags)

Read and execute statements from a file associated with an interactive deviceuntil EOF is reached. The user will be prompted usingsys.ps1 andsys.ps2.filename is decoded from thefilesystem encoding anderror handler. Returns0 at EOF or a negative number upon failure.

int(*PyOS_InputHook)(void)
為穩定 ABI 的一部分.

Can be set to point to a function with the prototypeintfunc(void). The function will be called when Python'sinterpreter prompt is about to become idle and wait for user inputfrom the terminal. The return value is ignored. Overriding thishook can be used to integrate the interpreter's prompt with otherevent loops, as done in theModules/_tkinter.c in thePython source code.

在 3.12 版的變更:This function is only called from themain interpreter.

char*(*PyOS_ReadlineFunctionPointer)(FILE*,FILE*,constchar*)

Can be set to point to a function with the prototypechar*func(FILE*stdin,FILE*stdout,char*prompt),overriding the default function used to read a single line of inputat the interpreter's prompt. The function is expected to outputthe stringprompt if it's notNULL, and then read a line ofinput from the provided standard input file, returning theresulting string. For example, Thereadline module setsthis hook to provide line-editing and tab-completion features.

The result must be a string allocated byPyMem_RawMalloc() orPyMem_RawRealloc(), orNULL if an error occurred.

在 3.4 版的變更:The result must be allocated byPyMem_RawMalloc() orPyMem_RawRealloc(), instead of being allocated byPyMem_Malloc() orPyMem_Realloc().

在 3.12 版的變更:This function is only called from themain interpreter.

PyObject*PyRun_String(constchar*str,intstart,PyObject*globals,PyObject*locals)
回傳值：新的參照。

This is a simplified interface toPyRun_StringFlags() below, leavingflags set toNULL.

PyObject*PyRun_StringFlags(constchar*str,intstart,PyObject*globals,PyObject*locals,PyCompilerFlags*flags)
回傳值：新的參照。

Execute Python source code fromstr in the context specified by theobjectsglobals andlocals with the compiler flags specified byflags.globals must be a dictionary;locals can be any objectthat implements the mapping protocol. The parameterstart specifiesthe start token that should be used to parse the source code.

Returns the result of executing the code as a Python object, orNULL if anexception was raised.

PyObject*PyRun_File(FILE*fp,constchar*filename,intstart,PyObject*globals,PyObject*locals)
回傳值：新的參照。

This is a simplified interface toPyRun_FileExFlags() below, leavingcloseit set to0 andflags set toNULL.

PyObject*PyRun_FileEx(FILE*fp,constchar*filename,intstart,PyObject*globals,PyObject*locals,intcloseit)
回傳值：新的參照。

This is a simplified interface toPyRun_FileExFlags() below, leavingflags set toNULL.

PyObject*PyRun_FileFlags(FILE*fp,constchar*filename,intstart,PyObject*globals,PyObject*locals,PyCompilerFlags*flags)
回傳值：新的參照。

This is a simplified interface toPyRun_FileExFlags() below, leavingcloseit set to0.

PyObject*PyRun_FileExFlags(FILE*fp,constchar*filename,intstart,PyObject*globals,PyObject*locals,intcloseit,PyCompilerFlags*flags)
回傳值：新的參照。

Similar toPyRun_StringFlags(), but the Python source code is read fromfp instead of an in-memory string.filename should be the name of the file,it is decoded from thefilesystem encoding and error handler.Ifcloseit is true, the file is closed beforePyRun_FileExFlags()returns.

PyObject*Py_CompileString(constchar*str,constchar*filename,intstart)
回傳值：新的參照。 為穩定 ABI 的一部分.

This is a simplified interface toPy_CompileStringFlags() below, leavingflags set toNULL.

PyObject*Py_CompileStringFlags(constchar*str,constchar*filename,intstart,PyCompilerFlags*flags)
回傳值：新的參照。

This is a simplified interface toPy_CompileStringExFlags() below, withoptimize set to-1.

PyObject*Py_CompileStringObject(constchar*str,PyObject*filename,intstart,PyCompilerFlags*flags,intoptimize)
回傳值：新的參照。

Parse and compile the Python source code instr, returning the resulting codeobject. The start token is given bystart; this can be used to constrain thecode which can be compiled and should bePy_eval_input,Py_file_input, orPy_single_input. The filename specified byfilename is used to construct the code object and may appear in tracebacks orSyntaxError exception messages. This returnsNULL if the codecannot be parsed or compiled.

The integeroptimize specifies the optimization level of the compiler; avalue of-1 selects the optimization level of the interpreter as given by-O options. Explicit levels are0 (no optimization;__debug__ is true),1 (asserts are removed,__debug__ is false)or2 (docstrings are removed too).

在 3.4 版被加入.

PyObject*Py_CompileStringExFlags(constchar*str,constchar*filename,intstart,PyCompilerFlags*flags,intoptimize)
回傳值：新的參照。

LikePy_CompileStringObject(), butfilename is a byte stringdecoded from thefilesystem encoding and error handler.

在 3.2 版被加入.

PyObject*PyEval_EvalCode(PyObject*co,PyObject*globals,PyObject*locals)
回傳值：新的參照。 為穩定 ABI 的一部分.

This is a simplified interface toPyEval_EvalCodeEx(), with justthe code object, and global and local variables. The other arguments areset toNULL.

PyObject*PyEval_EvalCodeEx(PyObject*co,PyObject*globals,PyObject*locals,PyObject*const*args,intargcount,PyObject*const*kws,intkwcount,PyObject*const*defs,intdefcount,PyObject*kwdefs,PyObject*closure)
回傳值：新的參照。 為穩定 ABI 的一部分.

Evaluate a precompiled code object, given a particular environment for itsevaluation. This environment consists of a dictionary of global variables,a mapping object of local variables, arrays of arguments, keywords anddefaults, a dictionary of default values forkeyword-only arguments and a closure tuple of cells.

PyObject*PyEval_EvalFrame(PyFrameObject*f)
回傳值：新的參照。 為穩定 ABI 的一部分.

Evaluate an execution frame. This is a simplified interface toPyEval_EvalFrameEx(), for backward compatibility.

PyObject*PyEval_EvalFrameEx(PyFrameObject*f,intthrowflag)
回傳值：新的參照。 為穩定 ABI 的一部分.

This is the main, unvarnished function of Python interpretation. The codeobject associated with the execution framef is executed, interpretingbytecode and executing calls as needed. The additionalthrowflagparameter can mostly be ignored - if true, then it causes an exceptionto immediately be thrown; this is used for thethrow()methods of generator objects.

在 3.4 版的變更:This function now includes a debug assertion to help ensure that itdoes not silently discard an active exception.

intPyEval_MergeCompilerFlags(PyCompilerFlags*cf)

This function changes the flags of the current evaluation frame, and returnstrue on success, false on failure.

intPy_eval_input

The start symbol from the Python grammar for isolated expressions; for use withPy_CompileString().

intPy_file_input

The start symbol from the Python grammar for sequences of statements as readfrom a file or other source; for use withPy_CompileString(). This isthe symbol to use when compiling arbitrarily long Python source code.

intPy_single_input

The start symbol from the Python grammar for a single statement; for use withPy_CompileString(). This is the symbol used for the interactiveinterpreter loop.

structPyCompilerFlags

This is the structure used to hold compiler flags. In cases where code is onlybeing compiled, it is passed asintflags, and in cases where code is beingexecuted, it is passed asPyCompilerFlags*flags. In this case,from__future__import can modifyflags.

WheneverPyCompilerFlags*flags isNULL,cf_flags is treated asequal to0, and any modification due tofrom__future__import isdiscarded.

intcf_flags

Compiler flags.

intcf_feature_version

cf_feature_version is the minor Python version. It should beinitialized toPY_MINOR_VERSION.

The field is ignored by default, it is used if and only ifPyCF_ONLY_AST flag is set incf_flags.

在 3.8 版的變更:新增cf_feature_version 欄位。

The available compiler flags are accessible as macros:

PyCF_ALLOW_TOP_LEVEL_AWAIT
PyCF_ONLY_AST
PyCF_OPTIMIZED_AST
PyCF_TYPE_COMMENTS

Seecompiler flags in documentation of theast Python module, which exports these constants underthe same names.

intCO_FUTURE_DIVISION

This bit can be set inflags to cause division operator/ to beinterpreted as "true division" according toPEP 238.