Python-inspect的使用

inspect模块提供了几个有用的函数来帮助获取有关于活动对象的信息，如模块、类、方法、函数、回溯、框架对象和代码对象。例如，它可以帮助您检查类的内容、检索方法的源代码、提取和格式化函数的参数列表，或者获得显示详细回溯所需的所有信息。下面来看一下inspect模块中一些常用的方法：

类型方法

getmodulename(path)

getmodulename根据路径获取模块名称

import os
from inspect import getmodulenamepath = os.path.join(os.getcwd(), "inspect.py")
name = getmodulename(path)
print(name, type(name))             # inspect_1 <class 'str'>name = getmodulename(os.getcwd())
print(name)                         # None

ismodule(object)

ismodule判断对象是否是模块

import os
from inspect import ismoduleclass Student(object):def __init__(self):self.name = "laozhang"self.age = 20print(ismodule(os))  # True
print(ismodule(Student()))  # False

isclass(object)

isclass判断对象是否是个类

from inspect import isclassclass Student(object):def __init__(self):self.name = "laozhang"self.age = 20print(isclass(Student))     # True
print(isclass(Student()))   # False

ismethod(object)

ismethod判断对象是否是个方法

from inspect import ismethodclass Student(object):def __init__(self):self.name = "laozhang"self.age = 20def say(self):print("hello world!")s = Student()
print(ismethod(s.say))   # True
print(ismethod(s.name))  # False

isfunction(object)

isfunction判断对象是否是个函数，包括匿名函数，不包括内置函数

from inspect import isfunctionclass Student(object):def __init__(self):self.name = "laozhang"self.age = 20def say(self):print("hello world!")def say():print("hello world!")s = Student()
print(isfunction(say))      # True
print(isfunction(s.say))    # False

isgeneratorfunction(object)

isgeneratorfunction判断对象是否是个生成器函数或方法，包括匿名函数

from inspect import isgeneratorfunctionclass Student(object):def __init__(self):self.name = "laozhang"self.age = 20def say(self):print("hello world!")yieldprint("hello python")yieldprint("hello java")def say():print("hello world!")yieldprint("hello python")yieldprint("hello java")s = Student()
g = (item for item in range(10))
print(isgeneratorfunction(say))     # True
print(isgeneratorfunction(s.say))   # True
print(isgeneratorfunction(g))       # False

isgenerator(object)

isgenerator判断是否是生成器，不包括函数或方法

from inspect import isgeneratordef say():print("hello world!")yieldprint("hello python")yieldprint("hello java")g = (item for item in range(10))print(isgenerator(say))     # False
print(isgenerator(say()))   # True
print(isgenerator(g))       # True

iscoroutinefunction(object)

iscoroutinefunction判断对象是否是由async def定义的协程函数

from inspect import iscoroutinefunctionasync def coroutine():print("coroutine")def func():n = 0yield nprint("OK")print(iscoroutinefunction(coroutine))   # True
print(iscoroutinefunction(func))        # False

iscoroutine(object)

iscoroutine判断对象是否是async def定义的函数创建的协程

from inpsect import iscoroutinedef say():print("hello world!")yieldprint("hello python")async def coroutine():print("coroutine")g = (item for item in range(10))
print(iscoroutine(say))             # False
print(iscoroutine(say()))           # False
print(iscoroutine(coroutine))       # False
print(iscoroutine(coroutine()))     # True
print(iscoroutine(g))               # False

isawaitable(object)

isawaitable如果对象可以用在await表达式中，则返回True。可用于区分基于生成器的协程和常规生成器

import asyncio
from inspect import isawaitabledef yield_func():print("yield_func_1")yieldprint("yield_func_2")async def asyncio_func():print("asyncio_func_1")r = await asyncio.sleep(1)print("asyncio_func_2")print(isawaitable(yield_func()))        # False
print(isawaitable(asyncio_func()))      # True

istraceback(object)

istraceback判断对象是否是回溯对象

import sys
from inspect import istraceback
try:raise TypeError
except TypeError:exec = sys.exc_info()print(exec)                             # (<class 'TypeError'>, TypeError(), <traceback object at 0x103c09788>)
print(istraceback(exec[2]))             # True

isframe(object)

isframe判断对象是否是frame对象

import sys
from inspect import isframetry:raise TypeError
except TypeError:exec = sys.exc_info()print(exec[2])                          # <traceback object at 0x103c29788>
print(exec[2].tb_frame)                 # <frame object at 0x101e07ad8>
print(isframe(exec[2].tb_frame))        # True

isbuiltin(object)

isbuiltin判断对象是否是内置函数

from inspect import isbuiltindef say():print("Hello World!")print(isbuiltin(say))           # False
print(isbuiltin(max))           # True

isroutine(object)

isroutine判断对象是否是内置函数、函数、方法或者方法描述符

from inspect import isroutineclass Student(object):def say(self):print("method hello world!")def say():print("Hello World!")print(isroutine(max))                   # True
print(isroutine(say))                   # True
print(isroutine(Student().say))         # True
print(isroutine(Student.__eq__))        # True

ismethoddescriptor(object)

ismethoddescriptor判断对象是否是个方法描述符，即判断该对象是否是有__get__()方法，没有__set__()方法。但如果ismethod()、isfunction()、isclass()或者isbuiltin()为True，则返回False

from inspect import ismethod
from inspect import ismethoddescriptorprint(ismethod(int.__add__))                # False
print(ismethoddescriptor(int.__add__))      # True

isdatadescriptor(object)

isdatadescriptor判断对象是否是个数据描述符，即判断该对象是否同时包含__set__()和__get__()方法。但如果ismethod()、isfunction()、isclass()或者isbuiltin()为True，则返回False

检索源代码

getdoc(object)

getdoc获取对象的文档字符串，如果没有则返回None

from inspect import getdocclass Student(object):"""Student类"""def __init__(self):passdef say():"""say函数"""print(getdoc(Student), type(getdoc(Student)))       # Student类 <class 'str'>
print(getdoc(say), type(getdoc(say)))               # say函数 <class 'str'>

getcomments(object)

getcomments以单个字符串的形式返回紧位于对象源代码(用于类、方法或者函数)之前的任何注释行，或者位于Python源文件的顶部(如果对象是个模块)。如果源代码不可用则返回None。

from inspect import getcomments# Student类
class Student(object):pass# say函数def say():passprint(getcomments(Student))         # # Student类
print(getcomments(say))             # None

getfile(object)

getfile返回定义对象的文件路径

from inspect import getfilen = 20
class Student(object):passdef say():passprint(getfile(Student))             # /Users/xxx/PycharmProjects/Demo/xxx/inspect_5.py
print(getfile(say)                  # /Users/xxx/PycharmProjects/Demo/xxx/inspect_5.py
print(getfile(Student()))           # TypeError: <__main__.Student object at 0x102ace9e8> is not a module, class, method, function, traceback, frame, or code object
print(getfile(say())                # TypeError: None is not a module, class, method, function, traceback, frame, or code object
print(getfile(max))                 # TypeError: <built-in function max> is not a module, class, method, function, traceback, frame, or code object
print(getfile(n))                   # TypeError: 20 is not a module, class, method, function, traceback, frame, or code object

getmodule(object)

getmodule尝试猜测对象定义在哪个模块当中

from inspect import getmodulen = 20
class Student(object):passdef say():passprint(getmodule(Student))           # <module '__main__' from '/Users/xxx/PycharmProjects/Demo/xxx用/inspect_5.py'>
print(getmodule(say))               # <module '__main__' from '/Users/xxx/PycharmProjects/Demo/xxx/inspect_5.py'>
print(getmodule(Student()))         # <module '__main__' from '/Users/xxx/PycharmProjects/Demo/xxx/inspect_5.py'>
print(getmodule(say()))             # None
print(getmodule(max))               # <module 'builtins' (built-in)>
print(getmodule(n))                 # None

更多操作：https://docs.python.org/3.6/library/inspect.html