30.13. inspect — Inspect live objects

Source code: Lib/inspect.py

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The inspect module provides several useful functions to help get information about live objects such as modules, classes, methods, functions, tracebacks, frame objects, and code objects. For example, it can help you examine the contents of a class, retrieve the source code of a method, extract and format the argument list for a function, or get all the information you need to display a detailed traceback.

There are four main kinds of services provided by this module: type checking, getting source code, inspecting classes and functions, and examining the interpreter stack.

30.13.1. Types and members

The getmembers() function retrieves the members of an object such as a class or module. The functions whose names begin with 「is」 are mainly provided as convenient choices for the second argument to getmembers(). They also help you determine when you can expect to find the following special attributes:

Type	Attribute	描述
module	__doc__	documentation string
	__file__	filename (missing for built-in modules)
class	__doc__	documentation string
	__name__	name with which this class was defined
	__qualname__	qualified name
	__module__	name of module in which this class was defined
method	__doc__	documentation string
	__name__	name with which this method was defined
	__qualname__	qualified name
	__func__	function object containing implementation of method
	__self__	instance to which this method is bound, or None
function	__doc__	documentation string
	__name__	name with which this function was defined
	__qualname__	qualified name
	__code__	code object containing compiled function bytecode
	__defaults__	tuple of any default values for positional or keyword parameters
	__kwdefaults__	mapping of any default values for keyword-only parameters
	__globals__	global namespace in which this function was defined
	__annotations__	mapping of parameters names to annotations; "return" key is reserved for return annotations.
traceback	tb_frame	frame object at this level
	tb_lasti	index of last attempted instruction in bytecode
	tb_lineno	current line number in Python source code
	tb_next	next inner traceback object (called by this level)
frame	f_back	next outer frame object (this frame’s caller)
	f_builtins	builtins namespace seen by this frame
	f_code	code object being executed in this frame
	f_globals	global namespace seen by this frame
	f_lasti	index of last attempted instruction in bytecode
	f_lineno	current line number in Python source code
	f_locals	local namespace seen by this frame
	f_restricted	0 or 1 if frame is in restricted execution mode
	f_trace	tracing function for this frame, or None
code	co_argcount	number of arguments (not including keyword only arguments, * or ** args)
	co_code	string of raw compiled bytecode
	co_cellvars	tuple of names of cell variables (referenced by containing scopes)
	co_consts	tuple of constants used in the bytecode
	co_filename	name of file in which this code object was created
	co_firstlineno	number of first line in Python source code
	co_flags	bitmap of CO_* flags, read more here
	co_lnotab	encoded mapping of line numbers to bytecode indices
	co_freevars	tuple of names of free variables (referenced via a function’s closure)
	co_kwonlyargcount	number of keyword only arguments (not including ** arg)
	co_name	name with which this code object was defined
	co_names	tuple of names of local variables
	co_nlocals	number of local variables
	co_stacksize	virtual machine stack space required
	co_varnames	tuple of names of arguments and local variables