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.
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.
Py_BytesMain
(int argc, char **argv)Similar to Py_Main()
but argv is an array of bytes strings.
New in version 3.8.
PyRun_AnyFile
(FILE *fp, const char *filename)PyRun_AnyFileExFlags()
below, leaving closeit set to 0
and flags set to NULL
.PyRun_AnyFileFlags
(FILE *fp, const char *filename, PyCompilerFlags *flags)PyRun_AnyFileExFlags()
below, leaving the closeit argument set to 0
.PyRun_AnyFileEx
(FILE *fp, const char *filename, int closeit)PyRun_AnyFileExFlags()
below, leaving the flags argument set to NULL
.PyRun_AnyFileExFlags
(FILE *fp, const char *filename, int closeit, PyCompilerFlags *flags)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.PyRun_SimpleString
(const char *command)PyRun_SimpleStringFlags()
below, leaving the PyCompilerFlags
* argument set to NULL
.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.
PyRun_SimpleFile
(FILE *fp, const char *filename)PyRun_SimpleFileExFlags()
below, leaving closeit set to 0
and flags set to NULL
.PyRun_SimpleFileEx
(FILE *fp, const char *filename, int closeit)PyRun_SimpleFileExFlags()
below, leaving flags set to NULL
.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.
Note
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.
PyRun_InteractiveOne
(FILE *fp, const char *filename)PyRun_InteractiveOneFlags()
below, leaving flags set to NULL
.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.)
PyRun_InteractiveLoop
(FILE *fp, const char *filename)PyRun_InteractiveLoopFlags()
below, leaving flags set to NULL
.PyRun_InteractiveLoopFlags
(FILE *fp, const char *filename, PyCompilerFlags *flags)sys.ps1
and sys.ps2
. filename is decoded from the filesystem encoding (sys.getfilesystemencoding()
). Returns 0
at EOF or a negative number upon failure.(*PyOS_InputHook)
(void)int func(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.(*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.
Changed in version 3.4: The result must be allocated by PyMem_RawMalloc()
or
PyMem_RawRealloc()
, instead of being allocated by
PyMem_Malloc()
or PyMem_Realloc()
.
PyParser_SimpleParseString
(const char *str, int start)PyParser_SimpleParseStringFlagsFilename()
below, leaving filename set to NULL
and flags set to 0
.PyParser_SimpleParseStringFlags
(const char *str, int start, int flags)PyParser_SimpleParseStringFlagsFilename()
below, leaving filename set to NULL
.PyParser_SimpleParseStringFlagsFilename
(const char *str, const char *filename, int start, int flags)sys.getfilesystemencoding()
).PyParser_SimpleParseFile
(FILE *fp, const char *filename, int start)PyParser_SimpleParseFileFlags()
below, leaving flags set to 0
.PyParser_SimpleParseFileFlags
(FILE *fp, const char *filename, int start, int flags)PyParser_SimpleParseStringFlagsFilename()
, but the Python source code is read from fp instead of an in-memory string.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
.
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.
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
.
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
.
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
.
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.
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
.
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
.
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).
New in version 3.4.
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()
).
New in version 3.2.
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
.
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
PyEval_EvalFrame
(PyFrameObject *f)Return value: New reference.
Evaluate an execution frame. This is a simplified interface to
PyEval_EvalFrameEx()
, for backward compatibility.
PyEval_EvalFrameEx
(PyFrameObject *f, int throwflag)Return value: New reference.
This is the main, unvarnished function of Python interpretation. 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.
Changed in version 3.4: This function now includes a debug assertion to help ensure that it does not silently discard an active exception.
PyEval_MergeCompilerFlags
(PyCompilerFlags *cf)Py_eval_input
Py_CompileString()
.Py_file_input
Py_CompileString()
. This is the symbol to use when compiling arbitrarily long Python source code.Py_single_input
Py_CompileString()
. This is the symbol used for the interactive interpreter loop.PyCompilerFlags
This is the structure used to hold compiler flags. In cases where code is only
being compiled, it is passed as int flags
, 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.
cf_flags
Compiler flags.
cf_feature_version
cf_feature_version is the minor Python version. It should be
initialized to PY_MINOR_VERSION
.
The field is ignored by default, it is used if and only if
PyCF_ONLY_AST
flag is set in cf_flags.
Changed in version 3.8: Added cf_feature_version field.
CO_FUTURE_DIVISION
/
to be interpreted as “true division” according to PEP 238.