PythonTheVeryHighLevelLayer

• Z时代
• 2024-01-10
• 分类：综合

The functions in this chapter will let you execute Python source code given in a

file or a buffer, but they will not let you interact in a more detailed way with

the interpreter.

Several of these functions accept a start symbol from the grammar as a

parameter. The available start symbols are Py_eval_input,

Py_file_input, and Py_single_input. These are described

following the functions which accept them as parameters.

Note also that several of these functions take FILE* parameters. One

particular issue which needs to be handled carefully is that the FILE

structure for different C libraries can be different and incompatible. Under

Windows (at least), it is possible for dynamically linked extensions to actually

use different libraries, so care should be taken that FILE* parameters

are only passed to these functions if it is certain that they were created by

the same library that the Python runtime is using.

int Py_Main(int argc, wchar_t **argv)¶

The main program for the standard interpreter. This is made available for

programs which embed Python. The argc and argv parameters should be

prepared exactly as those which are passed to a C program's main()

function (converted to wchar_t according to the user's locale). It is

important to note that the argument list may be modified (but the contents of

the strings pointed to by the argument list are not). The return value will

be 0 if the interpreter exits normally (i.e., without an exception),

1 if the interpreter exits due to an exception, or 2 if the parameter

list does not represent a valid Python command line.

Note that if an otherwise unhandled SystemExit is raised, this

function will not return 1, but exit the process, as long as

Py_InspectFlag is not set.

int PyRun_AnyFile(FILE *fp, const char *filename)¶

This is a simplified interface to PyRun_AnyFileExFlags() below, leaving

closeit set to 0 and flags set to NULL.

int PyRun_AnyFileFlags(FILE *fp, const char *filename, PyCompilerFlags *flags)¶

This is a simplified interface to PyRun_AnyFileExFlags() below, leaving

the closeit argument set to 0.

int PyRun_AnyFileEx(FILE *fp, const char *filename, int closeit)¶

This is a simplified interface to PyRun_AnyFileExFlags() below, leaving

the flags argument set to NULL.

int PyRun_AnyFileExFlags(FILE *fp, const char *filename, int closeit, PyCompilerFlags *flags)¶

If fp refers to a file associated with an interactive device (console or

terminal input or Unix pseudo-terminal), return the value of

PyRun_InteractiveLoop(), otherwise return the result of

PyRun_SimpleFile(). filename is decoded from the filesystem

encoding (sys.getfilesystemencoding()). If filename is NULL, this

function uses "???" as the filename.

int PyRun_SimpleString(const char *command)¶

This is a simplified interface to PyRun_SimpleStringFlags() below,

leaving the PyCompilerFlags* argument set to NULL.

int PyRun_SimpleStringFlags(const char *command, PyCompilerFlags *flags)¶

Executes the Python source code from command in the __main__ module

according to the flags argument. If __main__ does not already exist, it

is created. Returns 0 on success or -1 if an exception was raised. If

there was an error, there is no way to get the exception information. For the

meaning of flags, see below.

Note that if an otherwise unhandled SystemExit is raised, this

function will not return -1, but exit the process, as long as

Py_InspectFlag is not set.

int PyRun_SimpleFile(FILE *fp, const char *filename)¶

This is a simplified interface to PyRun_SimpleFileExFlags() below,

leaving closeit set to 0 and flags set to NULL.

int PyRun_SimpleFileEx(FILE *fp, const char *filename, int closeit)¶

This is a simplified interface to PyRun_SimpleFileExFlags() below,

leaving flags set to NULL.

int PyRun_SimpleFileExFlags(FILE *fp, const char *filename, int closeit, PyCompilerFlags *flags)¶

Similar to PyRun_SimpleStringFlags(), but the Python source code is read

from fp instead of an in-memory string. filename should be the name of

the file, it is decoded from the filesystem encoding

(sys.getfilesystemencoding()). If closeit is true, the file is

closed before PyRun_SimpleFileExFlags returns.

注解

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.

int PyRun_InteractiveOne(FILE *fp, const char *filename)¶

This is a simplified interface to PyRun_InteractiveOneFlags() below,

leaving flags set to NULL.

int PyRun_InteractiveOneFlags(FILE *fp, const char *filename, PyCompilerFlags *flags)¶

Read and execute a single statement from a file associated with an

interactive device according to the flags argument. The user will be

prompted using sys.ps1 and sys.ps2. filename is decoded from the

filesystem encoding (sys.getfilesystemencoding()).

Returns 0 when the input was

executed successfully, -1 if there was an exception, or an error code

from the errcode.h include file distributed as part of Python if

there was a parse error. (Note that errcode.h is not included by

Python.h, so must be included specifically if needed.)

int PyRun_InteractiveLoop(FILE *fp, const char *filename)¶

This is a simplified interface to PyRun_InteractiveLoopFlags() below,

leaving flags set to NULL.

int PyRun_InteractiveLoopFlags(FILE *fp, const char *filename, PyCompilerFlags *flags)¶

Read and execute statements from a file associated with an interactive device

until EOF is reached. The user will be prompted using sys.ps1 and

sys.ps2. filename is decoded from the filesystem encoding

(sys.getfilesystemencoding()). Returns 0 at EOF or a negative

number upon failure.

int (*PyOS_InputHook)(void)¶

Can be set to point to a function with the prototype

intfunc(void). The function will be called when Python's

interpreter prompt is about to become idle and wait for user input

from the terminal. The return value is ignored. Overriding this

hook can be used to integrate the interpreter's prompt with other

event loops, as done in the Modules/_tkinter.c in the

Python source code.

char* (*PyOS_ReadlineFunctionPointer)(FILE *, FILE *, const char *)¶

Can be set to point to a function with the prototype

char*func(FILE*stdin,FILE*stdout,char*prompt),

overriding the default function used to read a single line of input

at the interpreter's prompt. The function is expected to output

the string prompt if it's not NULL, and then read a line of

input from the provided standard input file, returning the

resulting string. For example, The readline module sets

this hook to provide line-editing and tab-completion features.

The result must be a string allocated by PyMem_RawMalloc() or

PyMem_RawRealloc(), or NULL if an error occurred.

在 3.4 版更改: The result must be allocated by PyMem_RawMalloc() or

PyMem_RawRealloc(), instead of being allocated by

PyMem_Malloc() or PyMem_Realloc().

struct _node* PyParser_SimpleParseString(const char *str, int start)¶

This is a simplified interface to

PyParser_SimpleParseStringFlagsFilename() below, leaving filename set

to NULL and flags set to 0.

struct _node* PyParser_SimpleParseStringFlags(const char *str, int start, int flags)¶

This is a simplified interface to

PyParser_SimpleParseStringFlagsFilename() below, leaving filename set

to NULL.

struct _node* PyParser_SimpleParseStringFlagsFilename(const char *str, const char *filename, int start, int flags)¶

Parse Python source code from str using the start token start according to

the flags argument. The result can be used to create a code object which can

be evaluated efficiently. This is useful if a code fragment must be evaluated

many times. filename is decoded from the filesystem encoding

(sys.getfilesystemencoding()).

struct _node* PyParser_SimpleParseFile(FILE *fp, const char *filename, int start)¶

This is a simplified interface to PyParser_SimpleParseFileFlags() below,

leaving flags set to 0.

struct _node* PyParser_SimpleParseFileFlags(FILE *fp, const char *filename, int start, int flags)¶

Similar to PyParser_SimpleParseStringFlagsFilename(), but the Python

source code is read from fp instead of an in-memory string.

PyObject* PyRun_String(const char *str, int start, PyObject *globals, PyObject *locals)¶

Return value: New reference.

This is a simplified interface to PyRun_StringFlags() below, leaving

flags set to NULL.

PyObject* PyRun_StringFlags(const char *str, int start, PyObject *globals, PyObject *locals, PyCompilerFlags *flags)¶

Return value: New reference.

Execute Python source code from str in the context specified by the

objects globals and locals with the compiler flags specified by

flags. globals must be a dictionary; locals can be any object

that implements the mapping protocol. The parameter start specifies

the start token that should be used to parse the source code.

Returns the result of executing the code as a Python object, or NULL if an

exception was raised.

PyObject* PyRun_File(FILE *fp, const char *filename, int start, PyObject *globals, PyObject *locals)¶

Return value: New reference.

This is a simplified interface to PyRun_FileExFlags() below, leaving

closeit set to 0 and flags set to NULL.

PyObject* PyRun_FileEx(FILE *fp, const char *filename, int start, PyObject *globals, PyObject *locals, int closeit)¶

Return value: New reference.

This is a simplified interface to PyRun_FileExFlags() below, leaving

flags set to NULL.

PyObject* PyRun_FileFlags(FILE *fp, const char *filename, int start, PyObject *globals, PyObject *locals, PyCompilerFlags *flags)¶

Return value: New reference.

This is a simplified interface to PyRun_FileExFlags() below, leaving

closeit set to 0.

PyObject* PyRun_FileExFlags(FILE *fp, const char *filename, int start, PyObject *globals, PyObject *locals, int closeit, PyCompilerFlags *flags)¶

Return value: New reference.

Similar to PyRun_StringFlags(), but the Python source code is read from

fp instead of an in-memory string. filename should be the name of the file,

it is decoded from the filesystem encoding (sys.getfilesystemencoding()).

If closeit is true, the file is closed before PyRun_FileExFlags()

returns.

PyObject* Py_CompileString(const char *str, const char *filename, int start)¶

Return value: New reference.

This is a simplified interface to Py_CompileStringFlags() below, leaving

flags set to NULL.

PyObject* Py_CompileStringFlags(const char *str, const char *filename, int start, PyCompilerFlags *flags)¶

Return value: New reference.

This is a simplified interface to Py_CompileStringExFlags() below, with

optimize set to -1.

PyObject* Py_CompileStringObject(const char *str, PyObject *filename, int start, PyCompilerFlags *flags, int optimize)¶

Return value: New reference.

Parse and compile the Python source code in str, returning the resulting code

object. The start token is given by start; this can be used to constrain the

code which can be compiled and should be Py_eval_input,

Py_file_input, or Py_single_input. The filename specified by

filename is used to construct the code object and may appear in tracebacks or

SyntaxError exception messages. This returns NULL if the code

cannot be parsed or compiled.

The integer optimize specifies the optimization level of the compiler; a

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).

3.4 新版功能.

PyObject* Py_CompileStringExFlags(const char *str, const char *filename, int start, PyCompilerFlags *flags, int optimize)¶

Return value: New reference.

Like Py_CompileStringObject(), but filename is a byte string

decoded from the filesystem encoding (os.fsdecode()).

3.2 新版功能.

PyObject* PyEval_EvalCode(PyObject *co, PyObject *globals, PyObject *locals)¶

Return value: New reference.

This is a simplified interface to PyEval_EvalCodeEx(), with just

the code object, and global and local variables. The other arguments are

set to NULL.

PyObject* PyEval_EvalCodeEx(PyObject *co, PyObject *globals, PyObject *locals, PyObject *const *args, int argcount, PyObject *const *kws, int kwcount, PyObject *const *defs, int defcount, PyObject *kwdefs, PyObject *closure)¶

Return value: New reference.

Evaluate a precompiled code object, given a particular environment for its

evaluation. This environment consists of a dictionary of global variables,

a mapping object of local variables, arrays of arguments, keywords and

defaults, a dictionary of default values for keyword-only arguments and a closure tuple of cells.

PyFrameObject¶

The C structure of the objects used to describe frame objects. The

fields of this type are subject to change at any time.

PyObject* PyEval_EvalFrame(PyFrameObject *f)¶

Return value: New reference.

Evaluate an execution frame. This is a simplified interface to

PyEval_EvalFrameEx(), for backward compatibility.

PyObject* PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)¶

Return value: New reference.

This is the main, unvarnished function of Python interpretation. It is

literally 2000 lines long. The code object associated with the execution

frame f is executed, interpreting bytecode and executing calls as needed.

The additional throwflag parameter can mostly be ignored - if true, then

it causes an exception to immediately be thrown; this is used for the

throw() methods of generator objects.

在 3.4 版更改: 该函数现在包含一个调试断言，用以确保不会静默地丢弃活动的异常。

int PyEval_MergeCompilerFlags(PyCompilerFlags *cf)¶

This function changes the flags of the current evaluation frame, and returns

true on success, false on failure.

int Py_eval_input¶

The start symbol from the Python grammar for isolated expressions; for use with

Py_CompileString().

int Py_file_input¶

The start symbol from the Python grammar for sequences of statements as read

from a file or other source; for use with Py_CompileString(). This is

the symbol to use when compiling arbitrarily long Python source code.

int Py_single_input¶

The start symbol from the Python grammar for a single statement; for use with

Py_CompileString(). This is the symbol used for the interactive

interpreter loop.

struct PyCompilerFlags¶

This is the structure used to hold compiler flags. In cases where code is only

being compiled, it is passed as intflags, and in cases where code is being

executed, it is passed as PyCompilerFlags*flags. In this case, from

__future__import can modify flags.

Whenever PyCompilerFlags*flags is NULL, cf_flags is treated as

equal to 0, and any modification due to from__future__import is

discarded.

structPyCompilerFlags{
intcf_flags;
}

int CO_FUTURE_DIVISION¶

This bit can be set in flags to cause division operator / to be

interpreted as "true division" according to PEP 238.