Tools, FAQ, Tutorials:
'@...' Function Decorators
What are function decorators in Python?
✍: FYIcenter.com
A function decorator is shorthand notation to replace a function with a new version transformed by a wrapper function.
A function decorator can be specified using the following syntax:
@decorator_wrapper_function def func(): ...
Above Python code is actually equivalent to:
def old_func(): ... func = decorator_wrapper_function(func)
In other words, if a function is decorated, the call expression will call the decorated version of the function.
If multiple decorators are specified, the call expression will call the decorated of the decorated version of the function. So the following Python code:
@a @b @c def f: ...
is the same as:
def f: ... f = a(b(c(f)))
Here is the same example as the previous tutorial in the "@..." decorator format:
>>> def wrapper(dump): ... def newDump(user): ... x = dump(user) ... print("<root>") ... for item in user: ... print("<"+item+">"+str(user[item])+"</"+item+">") ... print("</root>") ... return x ... return newDump ... >>> @wrapper ... def dump(user): ... print(user) ... >>> guest = {"name": "Joe", "age": 25} >>> dump(guest) {'name': 'Joe', 'age': 25} <root> <name>Joe</name> <age>25</age> </root>
⇒ Defining and Using Class for New Data Types
2018-05-08, 2004🔥, 0💬
Popular Posts:
Where to find tutorials on Visual Studio? I want to know How to learn Visual Studio. Here is a large...
How to read RSS validation errors at w3.org? If your RSS feed has errors, the RSS validator at w3.or...
What is the Azure AD v1.0 OpenID Metadata Document? Azure AD v1.0 OpenID Metadata Document is an onl...
How to start Visual Studio Command Prompt? I have Visual Studio 2017 Community version with Visual C...
How to access URL template parameters from "context.Request.Matched Parameters"object in Azure API P...