runpy
— 定位和执行 Python 模块
¶
2.5 版新增。
源代码： Lib/runpy.py
The
runpy
module is used to locate and run Python modules without importing them first. Its main use is to implement the
-m
command line switch that allows scripts to be located using the Python module namespace rather than the filesystem.
The
runpy
模块提供 2 函数：
runpy.
run_module
(
mod_name
,
init_globals=None
,
run_name=None
,
alter_sys=False
)
¶
Execute the code of the specified module and return the resulting module globals dictionary. The module’s code is first located using the standard import mechanism (refer to PEP 302 for details) and then executed in a fresh module namespace.
If the supplied module name refers to a package rather than a normal module, then that package is imported and the
__main__
submodule within that package is then executed and the resulting module globals dictionary returned.
The optional dictionary argument
init_globals
may be used to pre-populate the module’s globals dictionary before the code is executed. The supplied dictionary will not be modified. If any of the special global variables below are defined in the supplied dictionary, those definitions are overridden by
run_module()
.
The special global variables
__name__
,
__file__
,
__loader__
and
__package__
are set in the globals dictionary before the module code is executed (Note that this is a minimal set of variables - other variables may be set implicitly as an interpreter implementation detail).
__name__
被设为
run_name
if this optional argument is not
None
，到
mod_name + '.__main__'
if the named module is a package and to the
mod_name
argument otherwise.
__file__
is set to the name provided by the module loader. If the loader does not make filename information available, this variable is set to
None
.
__loader__
被设为
PEP 302
module loader used to retrieve the code for the module (This loader may be a wrapper around the standard import mechanism).
__package__
被设为
mod_name
if the named module is a package and to
mod_name.rpartition('.')[0]
否则。
If the argument
alter_sys
is supplied and evaluates to
True
，那么
sys.argv[0]
is updated with the value of
__file__
and
sys.modules[__name__]
is updated with a temporary module object for the module being executed. Both
sys.argv[0]
and
sys.modules[__name__]
are restored to their original values before the function returns.
Note that this manipulation of
sys
is not thread-safe. Other threads may see the partially initialised module, as well as the altered list of arguments. It is recommended that the
sys
module be left alone when invoking this function from threaded code.
另请参阅
The
-m
option offering equivalent functionality from the command line.
2.7 版改变：
Added ability to execute packages by looking for a
__main__
submodule
runpy.
run_path
(
file_path
,
init_globals=None
,
run_name=None
)
¶
Execute the code at the named filesystem location and return the resulting module globals dictionary. As with a script name supplied to the CPython command line, the supplied path may refer to a Python source file, a compiled bytecode file or a valid sys.path entry containing a
__main__
module (e.g. a zipfile containing a top-level
__main__.py
file).
For a simple script, the specified code is simply executed in a fresh module namespace. For a valid sys.path entry (typically a zipfile or directory), the entry is first added to the beginning of
sys.path
. The function then looks for and executes a
__main__
module using the updated path. Note that there is no special protection against invoking an existing
__main__
entry located elsewhere on
sys.path
if there is no such module at the specified location.
The optional dictionary argument
init_globals
may be used to pre-populate the module’s globals dictionary before the code is executed. The supplied dictionary will not be modified. If any of the special global variables below are defined in the supplied dictionary, those definitions are overridden by
run_path()
.
The special global variables
__name__
,
__file__
,
__loader__
and
__package__
are set in the globals dictionary before the module code is executed (Note that this is a minimal set of variables - other variables may be set implicitly as an interpreter implementation detail).
__name__
被设为
run_name
if this optional argument is not
None
and to
'<run_path>'
否则。
__file__
is set to the name provided by the module loader. If the loader does not make filename information available, this variable is set to
None
. For a simple script, this will be set to
file_path
.
__loader__
被设为
PEP 302
module loader used to retrieve the code for the module (This loader may be a wrapper around the standard import mechanism). For a simple script, this will be set to
None
.
__package__
被设为
__name__.rpartition('.')[0]
.
A number of alterations are also made to the
sys
module. Firstly,
sys.path
may be altered as described above.
sys.argv[0]
is updated with the value of
file_path
and
sys.modules[__name__]
is updated with a temporary module object for the module being executed. All modifications to items in
sys
are reverted before the function returns.
Note that, unlike
run_module()
, the alterations made to
sys
are not optional in this function as these adjustments are essential to allowing the execution of sys.path entries. As the thread-safety limitations still apply, use of this function in threaded code should be either serialised with the import lock or delegated to a separate process.
另请参阅
接口选项
for equivalent functionality on the command line (
python path/to/script
).
2.7 版新增。
另请参阅
PEP written and implemented by Nick Coghlan.
PEP written and implemented by Nick Coghlan.
命令行和环境 - CPython command line details