>>> 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__']?

其中大多數(shù)是Python常規(guī)類都有的屬性，下面重點(diǎn)看看常規(guī)對(duì)象沒(méi)有而函數(shù)對(duì)象有的屬性：

>>> class C:pass
...
>>> obj = C()
>>> def func():pass
...
>>> sorted(set(dir(func)) - set(dir(obj))) # 計(jì)算差集，然后排序
['__annotations__', '__call__', '__closure__', '__code__', '__defaults__', '__get__', '__globals__', '__kwdefaults__', '__name__', '__qualname__']

對(duì)于上面列出的函數(shù)特有屬性，說(shuō)明如下：

__annotations__ dict 參數(shù)和返回值的注釋
__call__ method-wrapper 實(shí)現(xiàn)（）運(yùn)算符，即可調(diào)用對(duì)象的協(xié)議
__closure__ tuple 函數(shù)閉包，即自由變量的綁定（通常是None）
__code__ code 編譯成字節(jié)碼的函數(shù)元數(shù)據(jù)和函數(shù)定義體
__defaults__ tuple 形式參數(shù)的默認(rèn)值
__get__ method-wrapper 實(shí)現(xiàn)只讀描述符協(xié)議
__globals__ dict 函數(shù)所在的模塊中的全局變量
__kwdefaults__ dict 僅限關(guān)鍵字形式參數(shù)的默認(rèn)值
__name__ str 函數(shù)名稱
__qualname__ str 函數(shù)的限定名稱

定位參數(shù)和僅限關(guān)鍵字參數(shù)

def tag(name,*content,cls=None,**attrs):
if cls is not None:
attrs['class'] = cls

if attrs:
attrs_str = ''.join(' %s="%s" ' % (attr,value) for attr,value in sorted(attrs.items()))
else:
attrs_str=''
if content:
return '\n'.join('<%s %s >%s</%s>' % (name,attrs_str,c,name) for c in content)
else:
return '<%s%s />' % (name,attrs_str)
print(tag('br'))#定位參數(shù) name
print(tag('p','hello'))#hello 會(huì)被*conteng捕獲 存入元組content = ('hello')
print(tag('p','hello','world'))#content = ('hello','world')
print(tag('p','hello',id=33)) #attrs={'id':33} content = ('hello')
print(tag('p','hello','world',cls='sidebar'))#cls 關(guān)鍵字傳入 cls='sidebar'
print(tag(content='testing',name='img'))#第一個(gè)參數(shù)name 也能作為關(guān)鍵字傳入
#同名鍵會(huì)綁定到對(duì)應(yīng)的具名參數(shù)上，剩余的則會(huì)被**attrs捕獲
print(tag(**{'name':'img','title':'sunset boulevard','src':'sunset.jpg','cls':'framed'}))
#僅限關(guān)鍵字參數(shù)是python3.0新增的特性，在上例中，cls參數(shù)只能通過(guò)關(guān)鍵字參數(shù)指定，他一定不會(huì)捕獲未命名的定位參數(shù)
#定義函數(shù)時(shí)候，如果想指定僅限關(guān)鍵字參數(shù)，要把它們放到*的參數(shù)后面
def f(a,*,b):
return a,b
ff = f(1,b=2)
print(ff)

<br />
<p >hello</p>
<p >hello</p>
<p >world</p>
<p id="33" >hello</p>
<p class="sidebar" >hello</p>
<p class="sidebar" >world</p>
<img content="testing" />
<img class="framed" src="sunset.jpg" title="sunset boulevard" />
(1, 2)

inspect模板

def tag(name,*content,cls=None,**attrs):
if cls is not None:
attrs['class'] = cls
if attrs:
attrs_str = ''.join(' %s="%s" ' % (attr,value) for attr,value in sorted(attrs.items()))
else:
attrs_str=''
if content:
return '\n'.join('<%s %s >%s</%s>' % (name,attrs_str,c,name) for c in content)
else:
return '<%s%s />' % (name,attrs_str)
import inspect
sig = 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)

inspect模塊把實(shí)參綁定給函數(shù)調(diào)用：

(name, *content, cls=None, **attrs)
name = img
cls = framed
attrs = {'title': 'sun long', 'src': 'sunlong.jpg'}
<BoundArguments (name='img', cls='framed', attrs={'title': 'sun long', 'src': 'sunlong.jpg'})>

到此這篇關(guān)于python 函數(shù)定位參數(shù)+關(guān)鍵字參數(shù)+inspect模塊的文章就介紹到這了,更多相關(guān)python inspect模塊內(nèi)容請(qǐng)搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！

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