What does the “at” (@) symbol do in Python? - Stack Overflow
Jun 17, 2011 · An @ symbol at the beginning of a line is used for class and function decorators: PEP 318: Decorators. Python Decorators - Python Wiki. The most common Python decorators are: @property. @classmethod. @staticmethod. An @ in the middle of a line is probably matrix multiplication: @ as a binary operator.
python - Why do some functions have underscores "__" before …
In Python, the use of an underscore in a function name indicates that the function is intended for internal use and should not be called directly by users. It is a convention used to indicate that the function is "private" and not part of the public API of the module.
python - What does ** (double star/asterisk) and * (star/asterisk) …
Aug 31, 2008 · Also Python 3 adds a new semantic (refer PEP 3102): def func(arg1, arg2, arg3, *, kwarg1, kwarg2): pass Such function accepts only 3 positional arguments, and everything after * can only be passed as keyword arguments. Note: A Python dict, semantically used for keyword argument passing, is arbitrarily ordered. However, in Python 3.6+, keyword ...
What does -> mean in Python function definitions? - Stack Overflow
Jan 17, 2013 · Simply -> is introduced to get developers to optionally specify the return type of the function. See Python Enhancement Proposal 3107. This is an indication of how things may develop in future as Python is adopted extensively - an indication towards strong typing - this is my personal observation.
Overloaded functions in Python - Stack Overflow
11. Yes, it's possible. I wrote the code below in Python 3.2.1: def overload(*functions): return lambda *args, **kwargs: functions[len(args)](*args, **kwargs) Usage: myfunction=overload(no_arg_func, one_arg_func, two_arg_func) Note that the lambda returned by the overload functions choose a function to call depending on the number of unnamed ...
python - How to use a global variable in a function? - Stack Overflow
Python follows C in having only functions, and global variables generally imply side effects. An idiom like x = f(x) where f returns x, rather than f() with a "global x" declaration, is surely cleaner and clearer (as well as explicit rather than implicit).
Python nested functions variable scoping - Stack Overflow
Mar 7, 2011 · In Python 3, you can use the nonlocal statement to access non-local, non-global scopes. The nonlocal statement causes a variable definition to bind to a previously created variable in the nearest scope. Here are some examples to illustrate: def sum_list_items(_list): total = 0. def do_the_sum(_list): for i in _list:
python - Assigning a function to a variable - Stack Overflow
In python, functions are simply a type of variable, and can generally be used like any other variable. For example: def power_function(power): return lambda x : x**power power_function(3)(2) This returns 8. power_function is a function that returns a function as output.
What is the proper way to comment functions in Python?
Mar 2, 2010 · String literals occurring elsewhere in Python code may also act as documentation. They are not recognized by the Python bytecode compiler and are not accessible as runtime object attributes (i.e. not assigned to __doc__ ), but two types of extra docstrings may be extracted by software tools:
What is the naming convention in Python for variables and …
Coming from a C# background the naming convention for variables and methods are usually either camelCase or PascalCase: // C# example. string thisIsMyVariable = "a". public void ThisIsMyMethod() In Python, I have seen the above but I have also seen snake_case being used: # python example. this_is_my_variable = 'a'.