In Python, there's no "null" keyword. However, you can use the "None" keyword instead, which implies absence of value, null or "nothing". It can be returned from a function in any of the following ways: By returning None explicitly; By returning an empty return; By returning nothing...
如果return后面没有任何表达式,那么函数将返回None。None是 Python 中一个特殊的类型,表示没有值。 def do_nothing(): return result = do_nothing() # result 将会得到 None 1.3 立即退出函数 return语句不仅仅是用来返回值,它还会立即结束函数的执行。即使return后面还有代码,这些代码都不会执行。 def print_nu...
def do_nothing(): return def return_none(): return None print(do_nothing()) # 输出: None print(return_none()) # 输出: None 4. 使用列表和字典作为返回值 函数也可以返回列表、字典或其它复杂数据结构。 def square_numbers(nums): return [num * num for num in nums] squares = square_number...
For example, I’ve been using an “implicit return statement” in one of the code samples in an earlier revision of the book. I didn’t mention what I was doing- I just wanted a nice short code sample to explain some other feature in Python. Eventually I started getting a steady strea...
Python函数return(),return{}和return[]究竟有什么区别呀？[图片] Python函数return(),return{}和return...
一个证明它是表达式的例子是: val x = when (coin) { 0 -> 123 1 -> (return 456) as Nothing else -> error("unexpected coin value")} (runnable sample) 由于return ...表达式的类型为Nothing,因此将其用作其他复合表达式的一部分没有多大意义。然而,在某些情况下,它是方便的: val x = if (foo...
>>> def ret_Nothing(): ... return ... >>> def ret_None(): ... return None ... >>> def ret_0(): ... return 0 ... >>> ret_Nothing() == None True >>> ret_Nothing() is None # correct way to compare values with None True >>> ret_None() is None True >>> ret...
Python Tricks: Nothing to Return Here Python adds an implicit return None statement to the end of any function. Therefore, if a function doesn’t specify a return value, it returns None by default. This means you can replace return None statements with bare return statements or even leave th...
However, that’s not what happens, and you get nothing on your screen.Try it out by yourself. Save your script to a file called adding.py and run it from your command line as follows:Shell $ python3 adding.py If you run adding.py from your command line, then you won’t see any...
In the above-given example, we have used print function to print the output of the function. As you can see in the above example print function returns nothing but print the value directly as output. Theaddvalue()method defined by the def keyword takes two parameters. The parameters a and...