Added in version 3.8.
可以初始化 Python 采用 Py_InitializeFromConfig() 和 PyConfig 结构。可以预初始化它采用 Py_PreInitialize() 和 PyPreConfig 结构。
Py_InitializeFromConfig()
PyConfig
Py_PreInitialize()
PyPreConfig
有 2 种配置：
The Python 配置 can be used to build a customized Python which behaves as the regular Python. For example, environment variables and command line arguments are used to configure Python.
The 隔离配置 can be used to embed Python into an application. It isolates Python from the system. For example, environment variables are ignored, the LC_CTYPE locale is left unchanged and no signal handler is registered.
The Py_RunMain() 函数可以用于编写定制 Python 程序。
Py_RunMain()
另请参阅 初始化、定稿和线程 .
另请参阅
PEP 587 Python 初始化配置。
Example of customized Python always running in isolated mode:
int main(int argc, char **argv) { PyStatus status; PyConfig config; PyConfig_InitPythonConfig(&config); config.isolated = 1; /* Decode command line arguments. Implicitly preinitialize Python (in isolated mode). */ status = PyConfig_SetBytesArgv(&config, argc, argv); if (PyStatus_Exception(status)) { goto exception; } status = Py_InitializeFromConfig(&config); if (PyStatus_Exception(status)) { goto exception; } PyConfig_Clear(&config); return Py_RunMain(); exception: PyConfig_Clear(&config); if (PyStatus_IsExit(status)) { return status.exitcode; } /* Display the error message and exit the process with non-zero exit code */ Py_ExitStatusException(status); }
List of wchar_t* strings.
wchar_t*
若 length 非 0， 项 must be non- NULL and all strings must be non- NULL .
NULL
Methods:
追加 item to list .
Python must be preinitialized to call this function.
插入 item into list at index .
若 index >= list length, append item to list .
index must be greater than or equal to 0 .
0
Structure fields:
List length.
List items.
Structure to store an initialization function status: success, error or exit.
For an error, it can store the C function name which created the error.
Exit code. Argument passed to exit() .
exit()
Error message.
Name of the function which created an error, can be NULL .
Functions to create a status:
Success.
Initialization error with a message.
err_msg 不得为 NULL .
Memory allocation failure (out of memory).
Exit Python with the specified exit code.
Functions to handle a status:
Is the status an error or an exit? If true, the exception must be handled; by calling Py_ExitStatusException() 例如。
Py_ExitStatusException()
Is the result an error?
Is the result an exit?
调用 exit(exitcode) if status is an exit. Print the error message and exit with a non-zero exit code if status is an error. Must only be called if PyStatus_Exception(status) is non-zero.
exit(exitcode)
PyStatus_Exception(status)
注意
Internally, Python uses macros which set PyStatus.func , whereas functions to create a status set func to NULL .
PyStatus.func
func
范例：
PyStatus alloc(void **ptr, size_t size) { *ptr = PyMem_RawMalloc(size); if (*ptr == NULL) { return PyStatus_NoMemory(); } return PyStatus_Ok(); } int main(int argc, char **argv) { void *ptr; PyStatus status = alloc(&ptr, 16); if (PyStatus_Exception(status)) { Py_ExitStatusException(status); } PyMem_Free(ptr); return 0; }
Structure used to preinitialize Python.
Function to initialize a preconfiguration:
Initialize the preconfiguration with Python 配置 .
Initialize the preconfiguration with 隔离配置 .
Name of the Python memory allocators:
PYMEM_ALLOCATOR_NOT_SET ( 0 ): don’t change memory allocators (use defaults).
PYMEM_ALLOCATOR_NOT_SET
PYMEM_ALLOCATOR_DEFAULT ( 1 ): 默认内存分配器 .
PYMEM_ALLOCATOR_DEFAULT
1
PYMEM_ALLOCATOR_DEBUG ( 2 ): 默认内存分配器 with debug hooks .
PYMEM_ALLOCATOR_DEBUG
2
PYMEM_ALLOCATOR_MALLOC ( 3 ): use malloc() of the C library.
PYMEM_ALLOCATOR_MALLOC
3
malloc()
PYMEM_ALLOCATOR_MALLOC_DEBUG ( 4 ): force usage of malloc() with debug hooks .
PYMEM_ALLOCATOR_MALLOC_DEBUG
4
PYMEM_ALLOCATOR_PYMALLOC ( 5 ): Python pymalloc memory allocator .
PYMEM_ALLOCATOR_PYMALLOC
5
PYMEM_ALLOCATOR_PYMALLOC_DEBUG ( 6 ): Python pymalloc memory allocator with debug hooks .
PYMEM_ALLOCATOR_PYMALLOC_DEBUG
6
PYMEM_ALLOCATOR_PYMALLOC and PYMEM_ALLOCATOR_PYMALLOC_DEBUG are not supported if Python is configured using --without-pymalloc .
configured using --without-pymalloc
见 内存管理 .
默认： PYMEM_ALLOCATOR_NOT_SET .
Set the LC_CTYPE locale to the user preferred locale.
If equals to 0 , set coerce_c_locale and coerce_c_locale_warn members to 0 .
coerce_c_locale
coerce_c_locale_warn
见 区域设置编码 .
默认： 1 in Python config, 0 in isolated config.
If equals to 2 , coerce the C locale.
If equals to 1 , read the LC_CTYPE locale to decide if it should be coerced.
默认： -1 in Python config, 0 in isolated config.
-1
If non-zero, emit a warning if the C locale is coerced.
Python 开发模式 : see PyConfig.dev_mode .
PyConfig.dev_mode
默认： -1 按 Python 模式， 0 按隔离模式。
Isolated mode: see PyConfig.isolated .
PyConfig.isolated
默认： 0 按 Python 模式， 1 按隔离模式。
If non-zero:
Set PyPreConfig.utf8_mode to 0 ,
PyPreConfig.utf8_mode
Set PyConfig.filesystem_encoding to "mbcs" ,
PyConfig.filesystem_encoding
"mbcs"
Set PyConfig.filesystem_errors to "replace" .
PyConfig.filesystem_errors
"replace"
Initialized the from PYTHONLEGACYWINDOWSFSENCODING environment variable value.
PYTHONLEGACYWINDOWSFSENCODING
只可用于 Windows。 #ifdef MS_WINDOWS macro can be used for Windows specific code.
#ifdef MS_WINDOWS
默认： 0 .
If non-zero, Py_PreInitializeFromArgs() and Py_PreInitializeFromBytesArgs() parse their argv argument the same way the regular Python parses command line arguments: see 命令行自变量 .
Py_PreInitializeFromArgs()
Py_PreInitializeFromBytesArgs()
argv
使用 环境变量 ? See PyConfig.use_environment .
PyConfig.use_environment
默认： 1 in Python config and 0 in isolated config.
若非 0，启用 Python UTF-8 模式 .
设为 0 or 1 通过 -X utf8 命令行选项和 PYTHONUTF8 环境变量。
-X utf8
PYTHONUTF8
Also set to 1 若 LC_CTYPE 区域设置是 C or POSIX .
LC_CTYPE
C
POSIX
默认： -1 in Python config and 0 in isolated config.
Python 的预初始化：
Set the Python memory allocators ( PyPreConfig.allocator )
PyPreConfig.allocator
Configure the LC_CTYPE locale ( 区域设置编码 )
设置 Python UTF-8 模式 ( PyPreConfig.utf8_mode )
The current preconfiguration ( PyPreConfig type) is stored in _PyRuntime.preconfig .
_PyRuntime.preconfig
Functions to preinitialize Python:
Preinitialize Python from preconfig preconfiguration.
preconfig 不得为 NULL .
剖析 argv command line arguments (bytes strings) if parse_argv of preconfig is non-zero.
parse_argv
剖析 argv command line arguments (wide strings) if parse_argv of preconfig is non-zero.
调用者负责处理异常 (错误或退出) 使用 PyStatus_Exception() and Py_ExitStatusException() .
PyStatus_Exception()
For Python 配置 ( PyPreConfig_InitPythonConfig() ), if Python is initialized with command line arguments, the command line arguments must also be passed to preinitialize Python, since they have an effect on the pre-configuration like encodings. For example, the -X utf8 command line option enables the Python UTF-8 模式 .
PyPreConfig_InitPythonConfig()
PyMem_SetAllocator() can be called after Py_PreInitialize() and before Py_InitializeFromConfig() to install a custom memory allocator. It can be called before Py_PreInitialize() if PyPreConfig.allocator 被设为 PYMEM_ALLOCATOR_NOT_SET .
PyMem_SetAllocator()
Python memory allocation functions like PyMem_RawMalloc() must not be used before the Python preinitialization, whereas calling directly malloc() and free() is always safe. Py_DecodeLocale() must not be called before the Python preinitialization.
PyMem_RawMalloc()
free()
Py_DecodeLocale()
Example using the preinitialization to enable the Python UTF-8 模式 :
PyStatus status; PyPreConfig preconfig; PyPreConfig_InitPythonConfig(&preconfig); preconfig.utf8_mode = 1; status = Py_PreInitialize(&preconfig); if (PyStatus_Exception(status)) { Py_ExitStatusException(status); } /* at this point, Python speaks UTF-8 */ Py_Initialize(); /* ... use Python API here ... */ Py_Finalize();
Structure containing most parameters to configure Python.
When done, the PyConfig_Clear() function must be used to release the configuration memory.
PyConfig_Clear()
Structure 方法：
Initialize configuration with the Python 配置 .
Initialize configuration with the 隔离配置 .
Copy the wide character string str into *config_str .
*config_str
预初始化 Python 若需要。
解码 str 使用 Py_DecodeLocale() and set the result into *config_str .
设置命令行自变量 ( argv member of config ) from the argv list of wide character strings.
设置命令行自变量 ( argv member of config ) from the argv list of bytes strings. Decode bytes using Py_DecodeLocale() .
设置宽字符串列表 list to length and 项 .
读取所有 Python 配置。
Fields which are already initialized are left unchanged.
Fields for 路径配置 are no longer calculated or modified when calling this function, as of Python 3.11.
The PyConfig_Read() function only parses PyConfig.argv arguments once: PyConfig.parse_argv 被设为 2 after arguments are parsed. Since Python arguments are strippped from PyConfig.argv , parsing arguments twice would parse the application options as Python options.
PyConfig_Read()
PyConfig.argv
PyConfig.parse_argv
3.10 版改变： The PyConfig.argv arguments are now only parsed once, PyConfig.parse_argv 被设为 2 after arguments are parsed, and arguments are only parsed if PyConfig.parse_argv 等于 1 .
3.11 版改变： PyConfig_Read() no longer calculates all paths, and so fields listed under Python 路径配置 may no longer be updated until Py_InitializeFromConfig() 被调用。
Release configuration memory.
Most PyConfig 方法 preinitialize Python if needed. In that case, the Python preinitialization configuration ( PyPreConfig ) in based on the PyConfig . If configuration fields which are in common with PyPreConfig are tuned, they must be set before calling a PyConfig 方法：
Moreover, if PyConfig_SetArgv() or PyConfig_SetBytesArgv() is used, this method must be called before other methods, since the preinitialization configuration depends on command line arguments (if parse_argv is non-zero).
PyConfig_SetArgv()
PyConfig_SetBytesArgv()
The caller of these methods is responsible to handle exceptions (error or exit) using PyStatus_Exception() and Py_ExitStatusException() .
Command line arguments: sys.argv .
sys.argv
Set parse_argv to 1 to parse argv the same way the regular Python parses Python command line arguments and then to strip Python arguments from argv .
若 argv is empty, an empty string is added to ensure that sys.argv always exists and is never empty.
默认： NULL .
另请参阅 orig_argv 成员。
orig_argv
If equals to zero, Py_RunMain() prepends a potentially unsafe path to sys.path at startup:
sys.path
若 argv[0] 等于 L"-m" ( python -m module ), prepend the current working directory.
argv[0]
L"-m"
python -m module
If running a script ( python script.py ), prepend the script’s directory. If it’s a symbolic link, resolve symbolic links.
python script.py
Otherwise ( python -c code and python ), prepend an empty string, which means the current working directory.
python -c code
python
设为 1 通过 -P 命令行选项和 PYTHONSAFEPATH 环境变量。
-P
PYTHONSAFEPATH
默认： 0 in Python config, 1 in isolated config.
Added in version 3.11.
sys.base_exec_prefix .
sys.base_exec_prefix
属于 Python 路径配置 输出。
Python base executable: sys._base_executable .
sys._base_executable
设置通过 __PYVENV_LAUNCHER__ 环境变量。
__PYVENV_LAUNCHER__
Set from PyConfig.executable if NULL .
PyConfig.executable
sys.base_prefix .
sys.base_prefix
If equals to 0 and configure_c_stdio is non-zero, disable buffering on the C streams stdout and stderr.
configure_c_stdio
设为 0 通过 -u 命令行选项和 PYTHONUNBUFFERED 环境变量。
-u
PYTHONUNBUFFERED
stdin is always opened in buffered mode.
默认： 1 .
If equals to 1 , issue a warning when comparing bytes or bytearray with str , or comparing bytes with int .
bytes
bytearray
str
int
If equal or greater to 2 ，引发 BytesWarning exception in these cases.
BytesWarning
Incremented by the -b 命令行选项。
-b
If non-zero, emit a EncodingWarning warning when io.TextIOWrapper uses its default encoding. See 选择加入 EncodingWarning 了解细节。
EncodingWarning
io.TextIOWrapper
Added in version 3.10.
If equals to 0 , disables the inclusion of the end line and column mappings in code objects. Also disables traceback printing carets to specific error locations.
设为 0 通过 PYTHONNODEBUGRANGES environment variable and by the -X no_debug_ranges 命令行选项。
PYTHONNODEBUGRANGES
-X no_debug_ranges
Control the validation behavior of hash-based .pyc files: value of the --check-hash-based-pycs 命令行选项。
.pyc
--check-hash-based-pycs
Valid values:
L"always" : Hash the source file for invalidation regardless of value of the ‘check_source’ flag.
L"always"
L"never" : Assume that hash-based pycs always are valid.
L"never"
L"default" : The ‘check_source’ flag in hash-based pycs determines invalidation.
L"default"
默认： L"default" .
另请参阅 PEP 552 “Deterministic pycs”.
If non-zero, configure C standard streams:
On Windows, set the binary mode ( O_BINARY ) on stdin, stdout and stderr.
O_BINARY
若 buffered_stdio equals zero, disable buffering of stdin, stdout and stderr streams.
buffered_stdio
若 interactive is non-zero, enable stream buffering on stdin and stdout (only stdout on Windows).
interactive
若非 0，启用 Python 开发模式 .
设为 1 通过 -X dev 选项和 PYTHONDEVMODE 环境变量。
-X dev
PYTHONDEVMODE
转储 Python 引用？
If non-zero, dump all objects which are still alive at exit.
设为 1 通过 PYTHONDUMPREFS 环境变量。
PYTHONDUMPREFS
Need a special build of Python with the Py_TRACE_REFS macro defined: see the configure --with-trace-refs option .
Py_TRACE_REFS
configure --with-trace-refs option
The site-specific directory prefix where the platform-dependent Python files are installed: sys.exec_prefix .
sys.exec_prefix
The absolute path of the executable binary for the Python interpreter: sys.executable .
sys.executable
Enable faulthandler?
If non-zero, call faulthandler.enable() at startup.
faulthandler.enable()
设为 1 by -X faulthandler 和 PYTHONFAULTHANDLER 环境变量。
-X faulthandler
PYTHONFAULTHANDLER
Filesystem encoding : sys.getfilesystemencoding() .
sys.getfilesystemencoding()
On macOS, Android and VxWorks: use "utf-8" 在默认情况下。
"utf-8"
在 Windows：使用 "utf-8" by default, or "mbcs" if legacy_windows_fs_encoding of PyPreConfig is non-zero.
legacy_windows_fs_encoding
Default encoding on other platforms:
"utf-8" if PyPreConfig.utf8_mode is non-zero.
"ascii" if Python detects that nl_langinfo(CODESET) announces the ASCII encoding, whereas the mbstowcs() function decodes from a different encoding (usually Latin1).
"ascii"
nl_langinfo(CODESET)
mbstowcs()
"utf-8" if nl_langinfo(CODESET) returns an empty string.
Otherwise, use the 区域设置编码 : nl_langinfo(CODESET) 结果。
At Python startup, the encoding name is normalized to the Python codec name. For example, "ANSI_X3.4-1968" 被替换采用 "ascii" .
"ANSI_X3.4-1968"
另请参阅 filesystem_errors 成员。
filesystem_errors
Filesystem error handler : sys.getfilesystemencodeerrors() .
sys.getfilesystemencodeerrors()
在 Windows：使用 "surrogatepass" by default, or "replace" if legacy_windows_fs_encoding of PyPreConfig is non-zero.
"surrogatepass"
在其它平台：使用 "surrogateescape" 在默认情况下。
"surrogateescape"
支持的错误处理程序：
"strict"
"surrogatepass" (only supported with the UTF-8 encoding)
另请参阅 filesystem_encoding 成员。
filesystem_encoding
Randomized hash function seed.
若 use_hash_seed is zero, a seed is chosen randomly at Python startup, and hash_seed 被忽略。
use_hash_seed
hash_seed
设置通过 PYTHONHASHSEED 环境变量。
PYTHONHASHSEED
默认 use_hash_seed 值： -1 按 Python 模式， 0 按隔离模式。
Python home directory.
若 Py_SetPythonHome() has been called, use its argument if it is not NULL .
Py_SetPythonHome()
设置通过 PYTHONHOME 环境变量。
PYTHONHOME
属于 Python 路径配置 输入。
If non-zero, profile import time.
设置 1 通过 -X importtime 选项和 PYTHONPROFILEIMPORTTIME 环境变量。
-X importtime
PYTHONPROFILEIMPORTTIME
Enter interactive mode after executing a script or a command.
若大于 0 , enable inspect: when a script is passed as first argument or the -c option is used, enter interactive mode after executing the script or the command, even when sys.stdin does not appear to be a terminal.
sys.stdin
Incremented by the -i command line option. Set to 1 若 PYTHONINSPECT environment variable is non-empty.
-i
PYTHONINSPECT
安装 Python 信号处理程序？
默认： 1 按 Python 模式， 0 按隔离模式。
若大于 0 , enable the interactive mode (REPL).
Incremented by the -i 命令行选项。
Configures the 整数字符串转换长度局限性 . An initial value of -1 means the value will be taken from the command line or environment or otherwise default to 4300 ( sys.int_info.default_max_str_digits ). A value of 0 disables the limitation. Values greater than zero but less than 640 ( sys.int_info.str_digits_check_threshold ) are unsupported and will produce an error.
sys.int_info.default_max_str_digits
sys.int_info.str_digits_check_threshold
Configured by the -X int_max_str_digits command line flag or the PYTHONINTMAXSTRDIGITS 环境变量。
-X int_max_str_digits
PYTHONINTMAXSTRDIGITS
默认： -1 in Python mode. 4300 ( sys.int_info.default_max_str_digits ) in isolated mode.
3.12 版添加。
若大于 0 , enable isolated mode:
Set safe_path to 1 : don’t prepend a potentially unsafe path to sys.path at Python startup, such as the current directory, the script’s directory or an empty string.
safe_path
Set use_environment to 0 : ignore PYTHON 环境变量。
use_environment
PYTHON
Set user_site_directory to 0 : don’t add the user site directory to sys.path .
user_site_directory
Python REPL doesn’t import readline nor enable default readline configuration on interactive prompts.
readline
设为 1 通过 -I 命令行选项。
-I
另请参阅 隔离配置 and PyPreConfig.isolated .
PyPreConfig.isolated
If non-zero, use io.FileIO 而不是 io._WindowsConsoleIO for sys.stdin , sys.stdout and sys.stderr .
io.FileIO
io._WindowsConsoleIO
sys.stdout
sys.stderr
设为 1 若 PYTHONLEGACYWINDOWSSTDIO 环境变量被设为非空字符串。
PYTHONLEGACYWINDOWSSTDIO
另请参阅 PEP 528 (Change Windows console encoding to UTF-8).
If non-zero, dump statistics on Python pymalloc memory allocator at exit.
设为 1 通过 PYTHONMALLOCSTATS 环境变量。
PYTHONMALLOCSTATS
The option is ignored if Python is configured using the --without-pymalloc option .
configured using the --without-pymalloc option
平台库目录名： sys.platlibdir .
sys.platlibdir
设置通过 PYTHONPLATLIBDIR 环境变量。
PYTHONPLATLIBDIR
Default: value of the PLATLIBDIR macro which is set by the configure --with-platlibdir option (default: "lib" ，或 "DLLs" 在 Windows)。
PLATLIBDIR
configure --with-platlibdir option
"lib"
"DLLs"
Added in version 3.9.
3.11 版改变： This macro is now used on Windows to locate the standard library extension modules, typically under DLLs . However, for compatibility, note that this value is ignored for any non-standard layouts, including in-tree builds and virtual environments.
DLLs
模块搜索路径 ( sys.path ) as a string separated by DELIM ( os.pathsep ).
DELIM
os.pathsep
设置通过 PYTHONPATH 环境变量。
PYTHONPATH
模块搜索路径： sys.path .
若 module_search_paths_set 等于 0 , Py_InitializeFromConfig() will replace module_search_paths 并设置 module_search_paths_set to 1 .
module_search_paths_set
module_search_paths
Default: empty list ( module_search_paths ) 和 0 ( module_search_paths_set ).
编译优化级别：
0 : Peephole optimizer, set __debug__ to True .
__debug__
True
1 : Level 0, remove assertions, set __debug__ to False .
False
2 : Level 1, strip docstrings.
Incremented by the -O command line option. Set to the PYTHONOPTIMIZE environment variable value.
-O
PYTHONOPTIMIZE
The list of the original command line arguments passed to the Python executable: sys.orig_argv .
sys.orig_argv
若 orig_argv list is empty and argv is not a list only containing an empty string, PyConfig_Read() copies argv into orig_argv before modifying argv (若 parse_argv is non-zero).
另请参阅 argv member and the Py_GetArgcArgv() 函数。
Py_GetArgcArgv()
默认：空列表。
Parse command line arguments?
If equals to 1 , parse argv the same way the regular Python parses command line arguments , and strip Python arguments from argv .
3.10 版改变： The PyConfig.argv arguments are now only parsed if PyConfig.parse_argv equals to 1 .
Parser debug mode. If greater than 0 , turn on parser debugging output (for expert only, depending on compilation options).
Incremented by the -d command line option. Set to the PYTHONDEBUG environment variable value.
-d
PYTHONDEBUG
需要 debug build of Python ( Py_DEBUG macro must be defined).
Py_DEBUG
If non-zero, calculation of path configuration is allowed to log warnings into stderr . If equals to 0 , suppress these warnings.
stderr
3.11 版改变： Now also applies on Windows.
The site-specific directory prefix where the platform independent Python files are installed: sys.prefix .
sys.prefix
Program name used to initialize executable and in early error messages during Python initialization.
executable
若 Py_SetProgramName() has been called, use its argument.
Py_SetProgramName()
On macOS, use PYTHONEXECUTABLE environment variable if set.
PYTHONEXECUTABLE
若 WITH_NEXT_FRAMEWORK macro is defined, use __PYVENV_LAUNCHER__ environment variable if set.
WITH_NEXT_FRAMEWORK
使用 argv[0] of argv if available and non-empty.
Otherwise, use L"python" on Windows, or L"python3" 在其它平台。
L"python"
L"python3"
Directory where cached .pyc files are written: sys.pycache_prefix .
sys.pycache_prefix
设置通过 -X pycache_prefix=PATH 命令行选项和 PYTHONPYCACHEPREFIX 环境变量。
-X pycache_prefix=PATH
PYTHONPYCACHEPREFIX
若 NULL , sys.pycache_prefix 被设为 None .
None
Quiet mode. If greater than 0 , don’t display the copyright and version at Python startup in interactive mode.
Incremented by the -q 命令行选项。
-q
Value of the -c 命令行选项。
-c
用于 Py_RunMain() .
Filename passed on the command line: trailing command line argument without -c or -m . It is used by the Py_RunMain() 函数。
-m
For example, it is set to script.py 通过 python3 script.py arg 命令行。
script.py
python3 script.py arg
另请参阅 PyConfig.skip_source_first_line 选项。
PyConfig.skip_source_first_line
Value of the -m 命令行选项。
Show total reference count at exit (excluding immortal objects)?
设为 1 by -X showrefcount 命令行选项。
-X showrefcount
需要 debug build of Python ( Py_REF_DEBUG macro must be defined).
Py_REF_DEBUG
导入 site module at startup?
site
If equal to zero, disable the import of the module site and the site-dependent manipulations of sys.path that it entails.
Also disable these manipulations if the site module is explicitly imported later (call site.main() 若想要触发它们)。
site.main()
设为 0 通过 -S 命令行选项。
-S
sys.flags.no_site is set to the inverted value of site_import .
sys.flags.no_site
site_import
If non-zero, skip the first line of the PyConfig.run_filename 源。
PyConfig.run_filename
It allows the usage of non-Unix forms of #!cmd . This is intended for a DOS specific hack only.
#!cmd
设为 1 通过 -x 命令行选项。
-x
Encoding and encoding errors of sys.stdin , sys.stdout and sys.stderr (但 sys.stderr always uses "backslashreplace" error handler).
"backslashreplace"
若 Py_SetStandardStreamEncoding() has been called, use its error and errors arguments if they are not NULL .
Py_SetStandardStreamEncoding()
使用 PYTHONIOENCODING environment variable if it is non-empty.
PYTHONIOENCODING
Default encoding:
"UTF-8" if PyPreConfig.utf8_mode is non-zero.
"UTF-8"
Otherwise, use the 区域设置编码 .
Default error handler:
在 Windows：使用 "surrogateescape" .
"surrogateescape" if PyPreConfig.utf8_mode is non-zero, or if the LC_CTYPE locale is “C” or “POSIX”.
"strict" 否则。
Enable tracemalloc?
If non-zero, call tracemalloc.start() at startup.
tracemalloc.start()
设置通过 -X tracemalloc=N command line option and by the PYTHONTRACEMALLOC 环境变量。
-X tracemalloc=N
PYTHONTRACEMALLOC
Enable compatibility mode with the perf profiler?
If non-zero, initialize the perf trampoline. See Python support for the Linux perf profiler 了解更多信息。
设置通过 -X perf command line option and by the PYTHONPERFSUPPORT 环境变量。
-X perf
PYTHONPERFSUPPORT
默认： -1 .
使用 环境变量 ?
If equals to zero, ignore the 环境变量 .
设为 0 通过 -E 环境变量。
-E
If non-zero, add the user site directory to sys.path .
设为 0 通过 -s and -I command line options.
-s
设为 0 通过 PYTHONNOUSERSITE 环境变量。
PYTHONNOUSERSITE
Verbose mode. If greater than 0 , print a message each time a module is imported, showing the place (filename or built-in module) from which it is loaded.
If greater than or equal to 2 , print a message for each file that is checked for when searching for a module. Also provides information on module cleanup at exit.
Incremented by the -v 命令行选项。
-v
设置通过 PYTHONVERBOSE environment variable value.
PYTHONVERBOSE
Options of the warnings module to build warnings filters, lowest to highest priority: sys.warnoptions .
warnings
sys.warnoptions
The warnings module adds sys.warnoptions in the reverse order: the last PyConfig.warnoptions item becomes the first item of warnings.filters which is checked first (highest priority).
PyConfig.warnoptions
warnings.filters
The -W command line options adds its value to warnoptions , it can be used multiple times.
-W
warnoptions
The PYTHONWARNINGS environment variable can also be used to add warning options. Multiple options can be specified, separated by commas ( , ).
PYTHONWARNINGS
,
若等于 0 ，Python 不会试着写入 .pyc files on the import of source modules.
设为 0 通过 -B 命令行选项和 PYTHONDONTWRITEBYTECODE 环境变量。
-B
PYTHONDONTWRITEBYTECODE
sys.dont_write_bytecode is initialized to the inverted value of write_bytecode .
sys.dont_write_bytecode
write_bytecode
Values of the -X 命令行选项： sys._xoptions .
-X
sys._xoptions
若 parse_argv 非 0， argv arguments are parsed the same way the regular Python parses command line arguments , and Python arguments are stripped from argv .
The xoptions options are parsed to set other options: see the -X 命令行选项。
xoptions
3.9 版改变： The show_alloc_count 字段被移除。
show_alloc_count
用于初始化 Python 的函数：
初始化 Python 从 config 配置。
若 PyImport_FrozenModules() , PyImport_AppendInittab() or PyImport_ExtendInittab() are used, they must be set or called after Python preinitialization and before the Python initialization. If Python is initialized multiple times, PyImport_AppendInittab() or PyImport_ExtendInittab() must be called before each Python initialization.
PyImport_FrozenModules()
PyImport_AppendInittab()
PyImport_ExtendInittab()
当前配置 ( PyConfig type) is stored in PyInterpreterState.config .
PyInterpreterState.config
范例设置程序名称：
void init_python(void) { PyStatus status; PyConfig config; PyConfig_InitPythonConfig(&config); /* Set the program name. Implicitly preinitialize Python. */ status = PyConfig_SetString(&config, &config.program_name, L"/path/to/my_program"); if (PyStatus_Exception(status)) { goto exception; } status = Py_InitializeFromConfig(&config); if (PyStatus_Exception(status)) { goto exception; } PyConfig_Clear(&config); return; exception: PyConfig_Clear(&config); Py_ExitStatusException(status); }
More complete example modifying the default configuration, read the configuration, and then override some parameters. Note that since 3.11, many parameters are not calculated until initialization, and so values cannot be read from the configuration structure. Any values set before initialize is called will be left unchanged by initialization:
PyStatus init_python(const char *program_name) { PyStatus status; PyConfig config; PyConfig_InitPythonConfig(&config); /* Set the program name before reading the configuration (decode byte string from the locale encoding). Implicitly preinitialize Python. */ status = PyConfig_SetBytesString(&config, &config.program_name, program_name); if (PyStatus_Exception(status)) { goto done; } /* Read all configuration at once */ status = PyConfig_Read(&config); if (PyStatus_Exception(status)) { goto done; } /* Specify sys.path explicitly */ /* If you want to modify the default set of paths, finish initialization first and then use PySys_GetObject("path") */ config.module_search_paths_set = 1; status = PyWideStringList_Append(&config.module_search_paths, L"/path/to/stdlib"); if (PyStatus_Exception(status)) { goto done; } status = PyWideStringList_Append(&config.module_search_paths, L"/path/to/more/modules"); if (PyStatus_Exception(status)) { goto done; } /* Override executable computed by PyConfig_Read() */ status = PyConfig_SetString(&config, &config.executable, L"/path/to/my_executable"); if (PyStatus_Exception(status)) { goto done; } status = Py_InitializeFromConfig(&config); done: PyConfig_Clear(&config); return status; }
PyPreConfig_InitIsolatedConfig() and PyConfig_InitIsolatedConfig() functions create a configuration to isolate Python from the system. For example, to embed Python into an application.
PyPreConfig_InitIsolatedConfig()
PyConfig_InitIsolatedConfig()
This configuration ignores global configuration variables, environment variables, command line arguments ( PyConfig.argv is not parsed) and user site directory. The C standard streams (ex: stdout ) and the LC_CTYPE locale are left unchanged. Signal handlers are not installed.
stdout
Configuration files are still used with this configuration to determine paths that are unspecified. Ensure PyConfig.home is specified to avoid computing the default path configuration.
PyConfig.home
PyPreConfig_InitPythonConfig() and PyConfig_InitPythonConfig() functions create a configuration to build a customized Python which behaves as the regular Python.
PyConfig_InitPythonConfig()
Environments variables and command line arguments are used to configure Python, whereas global configuration variables are ignored.
此函数启用 C 区域设置强制 ( PEP 538 ) 和 Python UTF-8 模式 ( PEP 540 ) 从属 LC_CTYPE 区域设置， PYTHONUTF8 and PYTHONCOERCECLOCALE 环境变量。
PYTHONCOERCECLOCALE
PyConfig 包含路径配置的多个字段：
路径配置输入：
PyConfig.platlibdir
PyConfig.pathconfig_warnings
PyConfig.program_name
PyConfig.pythonpath_env
current working directory: to get absolute paths
PATH environment variable to get the program full path (from PyConfig.program_name )
PATH
__PYVENV_LAUNCHER__ 环境变量
(Windows only) Application paths in the registry under “SoftwarePythonPythonCoreX.YPythonPath” of HKEY_CURRENT_USER and HKEY_LOCAL_MACHINE (where X.Y is the Python version).
路径配置输出字段：
PyConfig.base_exec_prefix
PyConfig.base_executable
PyConfig.base_prefix
PyConfig.exec_prefix
PyConfig.module_search_paths_set , PyConfig.module_search_paths
PyConfig.module_search_paths_set
PyConfig.module_search_paths
PyConfig.prefix
If at least one “output field” is not set, Python calculates the path configuration to fill unset fields. If module_search_paths_set 等于 0 , module_search_paths is overridden and module_search_paths_set 被设为 1 .
It is possible to completely ignore the function calculating the default path configuration by setting explicitly all path configuration output fields listed above. A string is considered as set even if it is non-empty. module_search_paths is considered as set if module_search_paths_set 被设为 1 。在此情况下， module_search_paths will be used without modification.
Set pathconfig_warnings to 0 to suppress warnings when calculating the path configuration (Unix only, Windows does not log any warning).
pathconfig_warnings
若 base_prefix or base_exec_prefix fields are not set, they inherit their value from prefix and exec_prefix 分别。
base_prefix
base_exec_prefix
prefix
exec_prefix
Py_RunMain() and Py_Main() 修改 sys.path :
Py_Main()
若 run_filename is set and is a directory which contains a __main__.py script, prepend run_filename to sys.path .
run_filename
__main__.py
若 isolated 为 0：
isolated
若 run_module is set, prepend the current directory to sys.path . Do nothing if the current directory cannot be read.
run_module
若 run_filename is set, prepend the directory of the filename to sys.path .
Otherwise, prepend an empty string to sys.path .
若 site_import 非 0， sys.path can be modified by the site module. If user_site_directory is non-zero and the user’s site-package directory exists, the site module appends the user’s site-package directory to sys.path .
The following configuration files are used by the path configuration:
pyvenv.cfg
._pth file (ex: python._pth )
._pth
python._pth
pybuilddir.txt (仅 Unix)
pybuilddir.txt
若 ._pth 文件存在：
Set isolated to 1 .
Set use_environment to 0 .
Set site_import to 0 .
Set safe_path to 1 .
The __PYVENV_LAUNCHER__ 环境变量用于设置 PyConfig.base_executable
执行命令 ( PyConfig.run_command )，脚本 ( PyConfig.run_filename ) 或模块 ( PyConfig.run_module ) specified on the command line or in the configuration.
PyConfig.run_command
PyConfig.run_module
By default and when if -i option is used, run the REPL.
Finally, finalizes Python and returns an exit status that can be passed to the exit() 函数。
见 Python 配置 for an example of customized Python always running in isolated mode using Py_RunMain() .
Get the original command line arguments, before Python modified them.
另请参阅 PyConfig.orig_argv 成员。
PyConfig.orig_argv
This section is a private provisional API introducing multi-phase initialization, the core feature of PEP 432 :
“Core” initialization phase, “bare minimum Python”:
Builtin types;
Builtin exceptions;
Builtin and frozen modules;
The sys module is only partially initialized (ex: sys.path doesn’t exist yet).
sys
“Main” initialization phase, Python is fully initialized:
Install and configure importlib ;
importlib
Apply the 路径配置 ;
Install signal handlers;
Finish sys module initialization (ex: create sys.stdout and sys.path );
Enable optional features like faulthandler and tracemalloc ;
faulthandler
tracemalloc
导入 site 模块；
etc.
Private provisional API:
PyConfig._init_main : if set to 0 , Py_InitializeFromConfig() stops at the “Core” initialization phase.
PyConfig._init_main
Move to the “Main” initialization phase, finish the Python initialization.
No module is imported during the “Core” phase and the importlib module is not configured: the 路径配置 is only applied during the “Main” phase. It may allow to customize Python in Python to override or tune the 路径配置 , maybe install a custom sys.meta_path importer or an import hook, etc.
sys.meta_path
It may become possible to calculate the 路径配置 in Python, after the Core phase and before the Main phase, which is one of the PEP 432 motivation.
The “Core” phase is not properly defined: what should be and what should not be available at this phase is not specified yet. The API is marked as private and provisional: the API can be modified or even be removed anytime until a proper public API is designed.
Example running Python code between “Core” and “Main” initialization phases:
void init_python(void) { PyStatus status; PyConfig config; PyConfig_InitPythonConfig(&config); config._init_main = 0; /* ... customize 'config' configuration ... */ status = Py_InitializeFromConfig(&config); PyConfig_Clear(&config); if (PyStatus_Exception(status)) { Py_ExitStatusException(status); } /* Use sys.stderr because sys.stdout is only created by _Py_InitializeMain() */ int res = PyRun_SimpleString( "import sys; " "print('Run Python code before _Py_InitializeMain', " "file=sys.stderr)"); if (res < 0) { exit(1); } /* ... put more configuration code here ... */ status = _Py_InitializeMain(); if (PyStatus_Exception(status)) { Py_ExitStatusException(status); } }
初始化、定稿和线程
内存管理
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