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Function introspection (function introspection)

In addition to the _ _ doc__ attribute, the function object has many properties. For the following functions, you can use dir () to view the properties that the function has:

> dir (factorial) ['_ _ annotations__','_ _ call__','_ _ class__','_ _ closure__','_ _ code__','_ _ defaults__','_ _ delattr__','_ _ dict__','_ dir__','_ doc__','_ eq__','_ format__','_ _ ge__','_ _ get__' '_ _ getattribute__',' _ _ globals__','_ _ gt__','_ _ hash__','_ _ init__','_ _ kwdefaults__','_ _ le__','_ _ lt__','_ _ module__','_ _ name__','_ ne__','_ new__','_ qualname__','_ _ reduce__' '_ _ reduce_ex__',' _ _ repr__','_ _ setattr__','_ _ sizeof__','_ _ str__','_ _ subclasshook__']

Most of these are properties that are common to Python regular classes. Let's focus on the properties that regular objects do not have but function objects have:

> class dir passthrough. > obj = C () > def func (): pass... > sorted (set (dir (func))-set (dir (obj) # calculate the difference Then sort ['_ _ annotations__','_ _ call__','_ _ closure__','_ _ code__','_ _ defaults__','_ _ get__','_ _ globals__','_ _ kwdefaults__','_ _ name__','_ _ qualname__']

The function-specific properties listed above are described as follows:

Comments for _ _ annotations__ dict parameters and return values

_ _ call__ method-wrapper implements the () operator, which calls the object's protocol

The _ _ closure__ tuple function closure, that is, the binding of free variables (usually None)

_ _ code__ code compiled into bytecode function metadata and function definition body

Default value of _ _ defaults__ tuple form parameter

_ _ get__ method-wrapper implements read-only descriptor protocol

Global variables in the module where the _ _ globals__ dict function is located

_ _ kwdefaults__ dict is limited to the default values of keyword form parameters only

_ _ name__ str function name

Qualified name of _ _ qualname__ str function

Location parameter and keyword parameter def tag (name,*content,cls=None,**attrs): if cls is not None:attrs ['class'] = clsif attrs:attrs_str =' .join ('% s''% (attr,value) for attr,value in sorted (attrs.items () else:attrs_str=''if content:return'\ n'.join ('% s'% (name,attrs_str,c) Name) for c in content) else:return''% (name,attrs_str) print (tag ('br')) # Positioning parameter nameprint (tag (' packs) hello.') # hello will be captured by * conteng and stored in the tuple content = ('hello') print (tag (' pawns) print (tag ('packs) print') Id=33) # attrs= {'id':33} content= (' hello') print (tag)) # cls keyword is passed into cls='sidebar'print (tag (content='testing',name='img')) # the first parameter name can also be passed as a keyword # the same name key will be bound to the corresponding named parameter The rest will be captured by * * attrs print (tag (* * {'name':'img','title':'sunset boulevard','src':'sunset.jpg','cls':'framed'})) # keyword parameter is a new feature of python3.0. In the above example, cls parameter can only be specified by keyword parameter, it will not capture unnamed positioning parameter # when defining function, if you want to specify keyword parameter only To put them after the parameters of * def f (a recorder): return a dagger bff = f (1 meme bau2) print (ff) hello

Hello

World

Hello

Hello

World

(1, 2) inspect template def tag (name,*content,cls=None,**attrs): if cls is not None:attrs ['class'] = clsif attrs:attrs_str =' .join ('% s "'% (attr,value) for attr,value in sorted (attrs.items () else:attrs_str=''if content:return'\ n'.join ('% s'% (name,attrs_str,c,name) for c in content) else:return'% (name) Attrs_str) import inspectsig = inspect.signature (tag) print (sig) my_tag = {'name':'img','title':'sun long','src':'sunlong.jpg','cls':'framed'} bound_args = sig.bind (* * my_tag) for name,value in bound_args.arguments.items (): print (name,'=',value) print (bound_args)

The inspect module binds arguments to function calls:

(name, * content, cls=None, * * attrs) name = imgcls = framedattrs = {'title':' sunlong', 'src':' sunlong.jpg'} Thank you for reading. The above is the content of "python parameters + keyword parameters + inspect module example analysis". After the study of this article, I believe you have a deeper understanding of the problem of python parameters + keyword parameters + inspect module example analysis. The specific use situation still needs to be verified by practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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