inspect — Inspect live objects

for an example.

inspect.ispackage(object)

Return True if the object is a

package

Added in version 3.14.

inspect.isgeneratorfunction(object)

Return True if the object is a Python generator function.

It also returns True for bound methods created from Python generator functions (see

Methods

for more information).

Changed in version 3.8: Functions wrapped in

functools.partialmethod()

now return True if the wrapped function is a Python generator function.

Changed in version 3.10.6:

Duck-typed

function-like objects now return True if their code object has the

CO_GENERATOR

flag.

Changed in version 3.13: Functions wrapped in

now return True if the wrapped function is a Python generator function.

inspect.isgenerator(object)

Return True if the object is a generator.

inspect.iscoroutinefunction(object)

Return True if the object is a

coroutine function

(a function defined with an

syntax), a

wrapping a coroutine function, or a sync function marked with

markcoroutinefunction()

Added in version 3.5.

Changed in version 3.10.6:

Duck-typed

function-like objects now return True if their code object has the

CO_COROUTINE

flag.

Changed in version 3.12: Sync functions marked with

markcoroutinefunction()

now return True.

inspect.markcoroutinefunction(func)

Decorator to mark a callable as a

coroutine function

if it would not otherwise be detected by

iscoroutinefunction()

This may be of use for sync functions that return a

coroutine

, if the function is passed to an API that requires

iscoroutinefunction()

When possible, using an

function is preferred. Also acceptable is calling the function and testing the return with

iscoroutine()

Added in version 3.12.

inspect.iscoroutine(object)

Return True if the object is a

coroutine

created by an

asynchronous generator iterator

function.

Added in version 3.5.

inspect.isawaitable(object)

Return True if the object can be used in

await

expression.

Can also be used to distinguish generator-based coroutines from regular generators:

importtypesdefgen():[email protected]_coro():yieldassertnotisawaitable(gen())assertisawaitable(gen_coro())Added in version 3.5.

inspect.isasyncgenfunction(object)

Return True if the object is an

asynchronous generator

function, for example:

>>> asyncdefagen():... yield1...>>> inspect.isasyncgenfunction(agen)TrueAdded in version 3.6.

Changed in version 3.10.6:

Duck-typed

function-like objects now return True if their code object has the

CO_ASYNC_GENERATOR

flag.

inspect.isasyncgen(object)

Return True if the object is an

created by an

asynchronous generator

function.

Added in version 3.6.

inspect.istraceback(object)

Return True if the object is a traceback.

inspect.isframe(object)

Return True if the object is a frame.

inspect.iscode(object)

Return True if the object is a code.

inspect.isbuiltin(object)

Return True if the object is a built-in function or a bound built-in method.

inspect.ismethodwrapper(object)

Return True if the type of object is a

MethodWrapperType

These are instances of

, such as

and

Added in version 3.11.

inspect.isroutine(object)

Return True if the object is a user-defined or built-in function or method.

inspect.isabstract(object)

Return True if the object is an abstract base class.

inspect.ismethoddescriptor(object)

Return True if the object is a method descriptor, but not if

isclass()

isfunction()

is true.

This, for example, is true of int.__add__. An object passing this test has a

method, but not a

method or a

method. Beyond that, the set of attributes varies. A

__name__

attribute is usually sensible, and

__doc__

often is.

Method descriptors that also pass any of the other tests (isclass(), ismethod() or isfunction()) make this function return False, simply because those other tests promise more – you can, for example, count on having the

__func__

attribute when an object passes

Changed in version 3.13: This function no longer incorrectly reports objects with

and

, but not

, as being method descriptors (such objects are data descriptors, not method descriptors).

inspect.isdatadescriptor(object)

Return True if the object is a data descriptor, but not if

isclass()

isfunction()

is true.

Data descriptors always have a

method and/or a

method. Optionally, they may also have a

method.

Examples of data descriptors are

properties

, getsets and member descriptors. Note that for the latter two (defined only in C extension modules), more specific tests are available:

isgetsetdescriptor()

and

ismemberdescriptor()

, respectively.

While data descriptors may also have

__name__

and __doc__ attributes (as properties, getsets and member descriptors do), this is not necessarily the case in general.

Changed in version 3.8: This function now reports objects with only a

method as being data descriptors (the presence of

is no longer required for that). Moreover, objects with

, but not __set__(), are now properly recognized as data descriptors as well, which was not the case previously.

inspect.isgetsetdescriptor(object)

Return True if the object is a getset descriptor.

CPython implementation detail: getsets are attributes defined in extension modules via

PyGetSetDef

structures. For Python implementations without such types, this method will always return False.

inspect.ismemberdescriptor(object)

Return True if the object is a member descriptor.

CPython implementation detail: Member descriptors are attributes defined in extension modules via

PyMemberDef

structures. For Python implementations without such types, this method will always return False.

Retrieving source code

inspect.getdoc(object, *, inherit_class_doc=True, fallback_to_class_doc=True, dedent=True)

Get the documentation string for an object, cleaned up with

cleandoc()

(with the same meaning of dedent). If the documentation string for an object is not provided:

if the object is a class and inherit_class_doc is true (by default), retrieve the documentation string from the inheritance hierarchy;

if the object is a method, a property or a descriptor, retrieve the documentation string from the inheritance hierarchy;

otherwise, if fallback_to_class_doc is true (by default), retrieve the documentation string from the class of the object.

Return None if the documentation string is invalid or missing.

Changed in version 3.5: Documentation strings are now inherited if not overridden.

Changed in version 3.15: Added parameters inherit_class_doc and fallback_to_class_doc.

Documentation strings on

cached_property

objects are now inherited if not overridden.

Changed in version 3.16.0a0 (unreleased): Added the dedent parameter.

Return in a single string any lines of comments immediately preceding the object’s source code (for a class, function, or method), or at the top of the Python source file (if the object is a module). If the object’s source code is unavailable, return None. This could happen if the object has been defined in C or the interactive shell.

inspect.getfile(object)

Return the name of the (text or binary) file in which an object was defined. An

is raised if the source code cannot be retrieved. This will fail with a

if the object is a built-in module, class, or function.

inspect.getmodule(object)

Try to guess which module an object was defined in. Return None if the module cannot be determined.

inspect.getsourcefile(object)

Return the name of the Python source file in which an object was defined or None if no way can be identified to get the source. An

is raised if the source code cannot be retrieved. This will fail with a

if the object is a built-in module, class, or function.

inspect.getsourcelines(object)

Return a list of source lines and starting line number for an object. The argument may be a module, class, method, function, traceback, frame, or code object. The source code is returned as a list of the lines corresponding to the object and the line number indicates where in the original source file the first line of code was found. An

is raised if the source code cannot be retrieved. A

is raised if the object is a built-in module, class, or function.

Changed in version 3.3:

is raised instead of

IOError

, now an alias of the former.

inspect.getsource(object)

Return the text of the source code for an object. The argument may be a module, class, method, function, traceback, frame, or code object. The source code is returned as a single string. An

is raised if the source code cannot be retrieved. A

is raised if the object is a built-in module, class, or function.

Changed in version 3.3:

is raised instead of

IOError

, now an alias of the former.

inspect.cleandoc(doc, *, dedent=True)

Clean up indentation from docstrings that are indented to line up with blocks of code.

All leading whitespace is removed from the first line. Any leading whitespace that can be uniformly removed from the second line onwards is removed, unless dedent is false. Empty lines at the beginning and end are subsequently removed. Also, all tabs are expanded to spaces.

Since Python 3.13 the compiler removes the indentation of docstrings, so dedent only affects documentation strings which are not written as docstrings in the source code, like those generated by Argument Clinic, where the indentation is meaningful.

Changed in version 3.16.0a0 (unreleased): Added the dedent parameter.

Introspecting callables with the Signature object

Added in version 3.3.

The

Signature

object represents the call signature of a callable object and its return annotation. To retrieve a Signature object, use the signature() function.

inspect.signature(callable, *, follow_wrapped=True, globals=None, locals=None, eval_str=False, annotation_format=Format.VALUE)

Return a

Signature

object for the given callable:

>>> frominspectimportsignature>>> deffoo(a,*,b:int,**kwargs):... pass>>> sig=signature(foo)>>> str(sig)'(a, *, b: int, **kwargs)'>>> str(sig.parameters['b'])'b: int'>>> sig.parameters['b'].annotation<class 'int'>Accepts a wide range of Python callables, from plain functions and classes to

objects.

If some of the annotations are strings (e.g., because from__future__importannotations was used), signature() will attempt to automatically un-stringize the annotations using

. The globals, locals, and eval_str parameters are passed into annotationlib.get_annotations() when resolving the annotations; see the documentation for annotationlib.get_annotations() for instructions on how to use these parameters. A member of the

annotationlib.Format

Raises

ValueError

if no signature can be provided, and

if that type of object is not supported. Also, if the annotations are stringized, and eval_str is not false, the eval() call(s) to un-stringize the annotations in

the FAQ entry on positional-only parameters

could potentially raise any kind of exception.

A slash (/) in the signature of a function denotes that the parameters prior to it are positional-only. For more info, see

Changed in version 3.5: The follow_wrapped parameter was added. Pass False to get a signature of callable specifically (callable.__wrapped__ will not be used to unwrap decorated callables.)

Changed in version 3.10: The globals, locals, and eval_str parameters were added.

Changed in version 3.14: The annotation_format parameter was added.

Note

Some callables may not be introspectable in certain implementations of Python. For example, in CPython, some built-in functions defined in C provide no metadata about their arguments.

CPython implementation detail: If the passed object has a __signature__ attribute, we may use it to create the signature. The exact semantics are an implementation detail and are subject to unannounced changes. Consult the source code for current semantics.

classinspect.Signature(parameters=None, *, return_annotation=Signature.empty)

A Signature object represents the call signature of a function and its return annotation. For each parameter accepted by the function it stores a

Parameter

object in its

parameters

collection.

The optional parameters argument is a sequence of

Parameter

objects, which is validated to check that there are no parameters with duplicate names, and that the parameters are in the right order, i.e. positional-only first, then positional-or-keyword, and that parameters with defaults follow parameters without defaults.

The optional return_annotation argument can be an arbitrary Python object. It represents the “return” annotation of the callable.

Signature objects are immutable. Use

Signature.replace()

to make a modified copy.

Changed in version 3.5: Signature objects are now picklable and

hashable

empty

A special class-level marker to specify absence of a return annotation.

parameters

An ordered mapping of parameters’ names to the corresponding

Parameter

objects. Parameters appear in strict definition order, including keyword-only parameters.

Changed in version 3.7: Python only explicitly guaranteed that it preserved the declaration order of keyword-only parameters as of version 3.7, although in practice this order had always been preserved in Python 3.

return_annotation

The “return” annotation for the callable. If the callable has no “return” annotation, this attribute is set to

Signature.empty

bind(*args, **kwargs)

Create a mapping from positional and keyword arguments to parameters. Returns

BoundArguments

if *args and **kwargs match the signature, or raises a

bind_partial(*args, **kwargs)

Works the same way as

, but allows the omission of some required arguments (mimics

behavior.) Returns

BoundArguments

, or raises a

if the passed arguments do not match the signature.

replace(*[,parameters][,return_annotation])

Create a new Signature instance based on the instance replace() was invoked on. It is possible to pass different parameters and/or return_annotation to override the corresponding properties of the base signature. To remove return_annotation from the copied Signature, pass in

Signature.empty

>>> deftest(a,b):... pass...>>> sig=signature(test)>>> new_sig=sig.replace(return_annotation="new return anno")>>> str(new_sig)"(a, b) -> 'new return anno'"Signature objects are also supported by the generic function

format(*, max_width=None, quote_annotation_strings=True)

Create a string representation of the Signature object.

If max_width is passed, the method will attempt to fit the signature into lines of at most max_width characters. If the signature is longer than max_width, all parameters will be on separate lines.

If quote_annotation_strings is False,

annotations

in the signature are displayed without opening and closing quotation marks if they are strings. This is useful if the signature was created with the

STRING

format or if from__future__importannotations was used.

Added in version 3.13.

Changed in version 3.14: The unquote_annotations parameter was added.

classmethodfrom_callable(obj, *, follow_wrapped=True, globals=None, locals=None, eval_str=False)

Return a Signature (or its subclass) object for a given callable obj.

This method simplifies subclassing of Signature:

classMySignature(Signature):passsig=MySignature.from_callable(sum)assertisinstance(sig,MySignature)Its behavior is otherwise identical to that of

Added in version 3.5.

Changed in version 3.10: The globals, locals, and eval_str parameters were added.

classinspect.Parameter(name, kind, *, default=Parameter.empty, annotation=Parameter.empty)

Parameter objects are immutable. Instead of modifying a Parameter object, you can use

Parameter.replace()

to create a modified copy.

Changed in version 3.5: Parameter objects are now picklable and

hashable

empty

A special class-level marker to specify absence of default values and annotations.

name

The name of the parameter as a string. The name must be a valid Python identifier.

CPython implementation detail: CPython generates implicit parameter names of the form .0 on the code objects used to implement comprehensions and generator expressions.

Changed in version 3.6: These parameter names are now exposed by this module as names like implicit0.

default

The default value for the parameter. If the parameter has no default value, this attribute is set to

Parameter.empty

annotation

The annotation for the parameter. If the parameter has no annotation, this attribute is set to

Parameter.empty

kind

Describes how argument values are bound to the parameter. The possible values are accessible via Parameter (like Parameter.KEYWORD_ONLY), and support comparison and ordering, in the following order:

Name

Meaning

POSITIONAL_ONLY

Value must be supplied as a positional argument. Positional only parameters are those which appear before a / entry (if present) in a Python function definition.

POSITIONAL_OR_KEYWORD

Value may be supplied as either a keyword or positional argument (this is the standard binding behaviour for functions implemented in Python.)

VAR_POSITIONAL

A tuple of positional arguments that aren’t bound to any other parameter. This corresponds to a *args parameter in a Python function definition.

KEYWORD_ONLY

Value must be supplied as a keyword argument. Keyword only parameters are those which appear after a * or *args entry in a Python function definition.

VAR_KEYWORD

A dict of keyword arguments that aren’t bound to any other parameter. This corresponds to a **kwargs parameter in a Python function definition.

Example: print all keyword-only arguments without default values:

>>> deffoo(a,b,*,c,d=10):... pass>>> sig=signature(foo)>>> forparaminsig.parameters.values():... if(param.kind==param.KEYWORD_ONLYand... param.defaultisparam.empty):... print('Parameter:',param)Parameter: ckind.description

Describes an enum value of

Parameter.kind

Added in version 3.8.

Example: print all descriptions of arguments:

>>> deffoo(a,b,*,c,d=10):... pass>>> sig=signature(foo)>>> forparaminsig.parameters.values():... print(param.kind.description)positional or keywordpositional or keywordkeyword-onlykeyword-onlyreplace(*[,name][,kind][,default][,annotation])

Create a new Parameter instance based on the instance replaced was invoked on. To override a Parameter attribute, pass the corresponding argument. To remove a default value or/and an annotation from a Parameter, pass

Parameter.empty

>>> frominspectimportParameter>>> param=Parameter('foo',Parameter.KEYWORD_ONLY,default=42)>>> str(param)'foo=42'>>> str(param.replace())# Will create a shallow copy of 'param''foo=42'>>> str(param.replace(default=Parameter.empty,annotation='spam'))"foo: 'spam'"Parameter objects are also supported by the generic function

Changed in version 3.4: In Python 3.3 Parameter objects were allowed to have name set to None if their kind was set to POSITIONAL_ONLY. This is no longer permitted.

classinspect.BoundArguments

Result of a

Signature.bind_partial()

call. Holds the mapping of arguments to the function’s parameters.

arguments

A mutable mapping of parameters’ names to arguments’ values. Contains only explicitly bound arguments. Changes in

arguments

will reflect in

args

and

kwargs

Should be used in conjunction with

Signature.parameters

for any argument processing purposes.

Note

Arguments for which

BoundArguments.apply_defaults()

Signature.bind_partial()

relied on a default value are skipped. However, if needed, use

to add them.

args

A tuple of positional arguments values. Dynamically computed from the

arguments

attribute.

kwargs

A dict of keyword arguments values. Dynamically computed from the

arguments

attribute. Arguments that can be passed positionally are included in

args

instead.

signature

A reference to the parent

Signature

object.

apply_defaults()

Set default values for missing arguments.

For variable-positional arguments (*args) the default is an empty tuple.

For variable-keyword arguments (**kwargs) the default is an empty dict.

>>> deffoo(a,b='ham',*args):pass>>> ba=inspect.signature(foo).bind('spam')>>> ba.apply_defaults()>>> ba.arguments{'a': 'spam', 'b': 'ham', 'args': ()}Added in version 3.5.

The

args

and

kwargs

properties can be used to invoke functions:

deftest(a,*,b):...sig=signature(test)ba=sig.bind(10,b=20)test(*ba.args,**ba.kwargs)See also

PEP 362

- Function Signature Object.The detailed specification, implementation details and examples.

Classes and functions

inspect.getclasstree(classes, unique=False)

Arrange the given list of classes into a hierarchy of nested lists. Where a nested list appears, it contains classes derived from the class whose entry immediately precedes the list. Each entry is a 2-tuple containing a class and a tuple of its base classes. If the unique argument is true, exactly one entry appears in the returned structure for each class in the given list. Otherwise, classes using multiple inheritance and their descendants will appear multiple times.

inspect.getfullargspec(func, *, annotation_format=Format.VALUE)

Get the names and default values of a Python function’s parameters. A

is returned:

FullArgSpec(args,varargs,varkw,defaults,kwonlyargs,kwonlydefaults,annotations)

args is a list of the positional parameter names. varargs is the name of the * parameter or None if arbitrary positional arguments are not accepted. varkw is the name of the ** parameter or None if arbitrary keyword arguments are not accepted. defaults is an n-tuple of default argument values corresponding to the last n positional parameters, or None if there are no such defaults defined. kwonlyargs is a list of keyword-only parameter names in declaration order. kwonlydefaults is a dictionary mapping parameter names from kwonlyargs to the default values used if no argument is supplied. annotations is a dictionary mapping parameter names to annotations. The special key "return" is used to report the function return value annotation (if any).

Note that

and

Signature Object

provide the recommended API for callable introspection, and support additional behaviours (like positional-only arguments) that are sometimes encountered in extension module APIs. This function is retained primarily for use in code that needs to maintain compatibility with the Python 2 inspect module API.

A member of the

annotationlib.Format

enum can be passed to the annotation_format parameter to control the format of the returned annotations. For example, use annotation_format=annotationlib.Format.STRING to return annotations in string format. Note that with the default VALUE format, creation of some argspecs may raise an exception.

Changed in version 3.4: This function is now based on

, but still ignores __wrapped__ attributes and includes the already bound first parameter in the signature output for bound methods.

Changed in version 3.6: This method was previously documented as deprecated in favour of

in Python 3.5, but that decision has been reversed in order to restore a clearly supported standard interface for single-source Python 2/3 code migrating away from the legacy getargspec() API.

Changed in version 3.15: The annotation_format parameter was added.

inspect.getargvalues(frame)

Get information about arguments passed into a particular frame. A

ArgInfo(args,varargs,keywords,locals) is returned. args is a list of the argument names. varargs and keywords are the names of the * and ** arguments or None. locals is the locals dictionary of the given frame.

Note

This function was inadvertently marked as deprecated in Python 3.5.

inspect.formatargvalues(args[, varargs, varkw, locals, formatarg, formatvarargs, formatvarkw, formatvalue])

Format a pretty argument spec from the four values returned by

getargvalues()

. The format* arguments are the corresponding optional formatting functions that are called to turn names and values into strings.

Note

This function was inadvertently marked as deprecated in Python 3.5.

inspect.getmro(cls)

Return a tuple of class cls’s base classes, including cls, in method resolution order. No class appears more than once in this tuple. Note that the method resolution order depends on cls’s type. Unless a very peculiar user-defined metatype is in use, cls will be the first element of the tuple.

inspect.getcallargs(func, /, *args, **kwds)

Bind the args and kwds to the argument names of the Python function or method func, as if it was called with them. For bound methods, bind also the first argument (typically named self) to the associated instance. A dict is returned, mapping the argument names (including the names of the * and ** arguments, if any) to their values from args and kwds. In case of invoking func incorrectly, i.e. whenever func(*args,**kwds) would raise an exception because of incompatible signature, an exception of the same type and the same or similar message is raised. For example:

>>> frominspectimportgetcallargs>>> deff(a,b=1,*pos,**named):... pass...>>> getcallargs(f,1,2,3)=={'a':1,'named':{},'b':2,'pos':(3,)}True>>> getcallargs(f,a=2,x=4)=={'a':2,'named':{'x':4},'b':1,'pos':()}True>>> getcallargs(f)Traceback (most recent call last):...TypeError: f() missing 1 required positional argument: 'a'Added in version 3.2.

Deprecated since version 3.5: Use

and

Signature.bind_partial()

instead.

inspect.getclosurevars(func)

Get the mapping of external name references in a Python function or method func to their current values. A

ClosureVars(nonlocals,globals,builtins,unbound) is returned. nonlocals maps referenced names to lexical closure variables, globals to the function’s module globals and builtins to the builtins visible from the function body. unbound is the set of names referenced in the function that could not be resolved at all given the current module globals and builtins.

is raised if func is not a Python function or method.

Added in version 3.3.

inspect.unwrap(func, *, stop=None)

Get the object wrapped by func. It follows the chain of __wrapped__ attributes returning the last object in the chain.

stop is an optional callback accepting an object in the wrapper chain as its sole argument that allows the unwrapping to be terminated early if the callback returns a true value. If the callback never returns a true value, the last object in the chain is returned as usual. For example,

uses this to stop unwrapping if any object in the chain has a __signature__ attribute defined.

ValueError

is raised if a cycle is encountered.

Added in version 3.4.

inspect.get_annotations(obj, *, globals=None, locals=None, eval_str=False, format=annotationlib.Format.VALUE)

Compute the annotations dict for an object.

This is an alias for

; see the documentation of that function for more information.

Added in version 3.10.

Changed in version 3.14: This function is now an alias for

. Calling it as inspect.get_annotations will continue to work.

The interpreter stack

Some of the following functions return

objects. For backwards compatibility these objects allow tuple-like operations on all attributes except positions. This behavior is considered deprecated and may be removed in the future.

classinspect.FrameInfo

frame

The

frame object

that the record corresponds to.

filename

The file name associated with the code being executed by the frame this record corresponds to.

lineno

The line number of the current line associated with the code being executed by the frame this record corresponds to.

function

The function name that is being executed by the frame this record corresponds to.

code_context

A list of lines of context from the source code that’s being executed by the frame this record corresponds to.

index

The index of the current line being executed in the

code_context

list.

positions

dis.Positions

object containing the start line number, end line number, start column offset, and end column offset associated with the instruction being executed by the frame this record corresponds to.

Changed in version 3.11: FrameInfo is now a class instance (that is backwards compatible with the previous

classinspect.Traceback

filename

The file name associated with the code being executed by the frame this traceback corresponds to.

lineno

The line number of the current line associated with the code being executed by the frame this traceback corresponds to.

function

The function name that is being executed by the frame this traceback corresponds to.

code_context

A list of lines of context from the source code that’s being executed by the frame this traceback corresponds to.

index

The index of the current line being executed in the

code_context

list.

positions

dis.Positions

object containing the start line number, end line number, start column offset, and end column offset associated with the instruction being executed by the frame this traceback corresponds to.

Changed in version 3.11: Traceback is now a class instance (that is backwards compatible with the previous

Note

Keeping references to frame objects, as found in the first element of the frame records these functions return, can cause your program to create reference cycles. Once a reference cycle has been created, the lifespan of all objects which can be accessed from the objects which form the cycle can become much longer even if Python’s optional cycle detector is enabled. If such cycles must be created, it is important to ensure they are explicitly broken to avoid the delayed destruction of objects and increased memory consumption which occurs.

Though the cycle detector will catch these, destruction of the frames (and local variables) can be made deterministic by removing the cycle in a

finally

clause. This is also important if the cycle detector was disabled when Python was compiled or using

gc.disable()

. For example:

defhandle_stackframe_without_leak():frame=inspect.currentframe()try:# do something with the framefinally:delframeIf you want to keep the frame around (for example to print a traceback later), you can also break reference cycles by using the

frame.clear()

method.

The optional context argument supported by most of these functions specifies the number of lines of context to return, which are centered around the current line.

inspect.getframeinfo(frame, context=1)

Get information about a frame or traceback object. A

Traceback

object is returned.

Changed in version 3.11: A

Traceback

object is returned instead of a named tuple.

inspect.getouterframes(frame, context=1)

Get a list of

objects for a frame and all outer frames. These frames represent the calls that lead to the creation of frame. The first entry in the returned list represents frame; the last entry represents the outermost call on frame’s stack.

Changed in version 3.5: A list of

FrameInfo(frame,filename,lineno,function,code_context,index) is returned.

Changed in version 3.11: A list of

objects is returned.

inspect.getinnerframes(traceback, context=1)

Get a list of

objects for a traceback’s frame and all inner frames. These frames represent calls made as a consequence of frame. The first entry in the list represents traceback; the last entry represents where the exception was raised.

Changed in version 3.5: A list of

FrameInfo(frame,filename,lineno,function,code_context,index) is returned.

Changed in version 3.11: A list of

objects is returned.

inspect.currentframe()

Return the frame object for the caller’s stack frame.

CPython implementation detail: This function relies on Python stack frame support in the interpreter, which isn’t guaranteed to exist in all implementations of Python. If running in an implementation without Python stack frame support this function returns None.

inspect.stack(context=1)

Return a list of

objects for the caller’s stack. The first entry in the returned list represents the caller; the last entry represents the outermost call on the stack.

Changed in version 3.5: A list of

FrameInfo(frame,filename,lineno,function,code_context,index) is returned.

Changed in version 3.11: A list of

objects is returned.

inspect.trace(context=1)

Return a list of

objects for the stack between the current frame and the frame in which an exception currently being handled was raised in. The first entry in the list represents the caller; the last entry represents where the exception was raised.

Changed in version 3.5: A list of

FrameInfo(frame,filename,lineno,function,code_context,index) is returned.

Changed in version 3.11: A list of

objects is returned.

Fetching attributes statically

Both

getattr()

and

hasattr()

can trigger code execution when fetching or checking for the existence of attributes. Descriptors, like properties, will be invoked and

__getattr__()

and

__getattribute__()

may be called.

For cases where you want passive introspection, like documentation tools, this can be inconvenient.

getattr_static()

has a similar signature as

getattr()

but avoids executing code when it fetches attributes.

inspect.getattr_static(obj, attr)

inspect.getattr_static(obj, attr, default)Retrieve attributes without triggering dynamic lookup via the descriptor protocol,

__getattr__()

__getattribute__()

Note: this function may not be able to retrieve all attributes that getattr can fetch (like dynamically created attributes) and may find attributes that getattr can’t (like descriptors that raise AttributeError). It can also return descriptors objects instead of instance members.

If the instance

__dict__

is shadowed by another member (for example a property) then this function will be unable to find instance members.

Added in version 3.2.

getattr_static()

does not resolve descriptors, for example slot descriptors or getset descriptors on objects implemented in C. The descriptor object is returned instead of the underlying attribute.

You can handle these with code like the following. Note that for arbitrary getset descriptors invoking these may trigger code execution:

# example code for resolving the builtin descriptor typesclass_foo:__slots__=['foo']slot_descriptor=type(_foo.foo)getset_descriptor=type(type(open(__file__)).name)wrapper_descriptor=type(str.__dict__['__add__'])descriptor_types=(slot_descriptor,getset_descriptor,wrapper_descriptor)result=getattr_static(some_object,'foo')iftype(result)indescriptor_types:try:result=result.__get__()exceptAttributeError:# descriptors can raise AttributeError to# indicate there is no underlying value# in which case the descriptor itself will# have to dopassCurrent State of Generators, Coroutines, and Asynchronous Generators

When implementing coroutine schedulers and for other advanced uses of generators, it is useful to determine whether a generator is currently executing, is waiting to start or resume or execution, or has already terminated.

getgeneratorstate()

allows the current state of a generator to be determined easily.

inspect.getgeneratorstate(generator)

Get current state of a generator-iterator.

Possible states are:

GEN_CREATED: Waiting to start execution.

GEN_RUNNING: Currently being executed by the interpreter.

GEN_SUSPENDED: Currently suspended at a yield expression.

GEN_CLOSED: Execution has completed.

Added in version 3.2.

inspect.getcoroutinestate(coroutine)

Get current state of a coroutine object. The function is intended to be used with coroutine objects created by

functions, but will accept any coroutine-like object that has cr_running and cr_frame attributes.

Possible states are:

CORO_CREATED: Waiting to start execution.

CORO_RUNNING: Currently being executed by the interpreter.

CORO_SUSPENDED: Currently suspended at an await expression.

CORO_CLOSED: Execution has completed.

Added in version 3.5.

inspect.getasyncgenstate(agen)

Get current state of an asynchronous generator object. The function is intended to be used with asynchronous iterator objects created by

functions which use the

yield

statement, but will accept any asynchronous generator-like object that has ag_running and ag_frame attributes.

Possible states are:

AGEN_CREATED: Waiting to start execution.

AGEN_RUNNING: Currently being executed by the interpreter.

AGEN_SUSPENDED: Currently suspended at a yield expression.

AGEN_CLOSED: Execution has completed.

Added in version 3.12.

The current internal state of the generator can also be queried. This is mostly useful for testing purposes, to ensure that internal state is being updated as expected:

inspect.getgeneratorlocals(generator)

Get the mapping of live local variables in generator to their current values. A dictionary is returned that maps from variable names to values. This is the equivalent of calling

locals()

in the body of the generator, and all the same caveats apply.

If generator is a

generator

with no currently associated frame, then an empty dictionary is returned.

is raised if generator is not a Python generator object.

CPython implementation detail: This function relies on the generator exposing a Python stack frame for introspection, which isn’t guaranteed to be the case in all implementations of Python. In such cases, this function will always return an empty dictionary.

Added in version 3.3.

inspect.getcoroutinelocals(coroutine)

This function is analogous to

getgeneratorlocals()

, but works for coroutine objects created by

functions.

Added in version 3.5.

inspect.getasyncgenlocals(agen)

This function is analogous to

getgeneratorlocals()

, but works for asynchronous generator objects created by