There’s no performance difference, as they compile to the same bytecode: >>> import dis >>> dis.dis(“not x is None”) 1 0 LOAD_NAME 0 (x) 2 LOAD_CONST 0 (None) 4 COMPARE_OP 9 (is not) 6 RETURN_VALUE >>> dis.dis(“x is not None”) 1 0 LOAD_NAME 0 (x) 2 LOAD_CONST 0 (None) 4 COMPARE_OP 9 (is not) 6 … Read more
In python the default return value of a function is None. >>> def func():pass >>> print func() #print or print() prints the return Value None >>> func() #remove print and the returned value is not printed. >>> So, just use: letter_grade(score) #remove the print Another alternative is to replace all prints with return: def letter_grade(score): … Read more
NoneType is the type for the None object, which is an object that indicates no value. None is the return value of functions that “don’t return anything”. It is also a common default return value for functions that search for something and may or may not find it; for example, it’s returned by re.search when … Read more
if val is not None: # … is the Pythonic idiom for testing that a variable is not set to None. This idiom has particular uses in the case of declaring keyword functions with default parameters. is tests identity in Python. Because there is one and only one instance of None present in a running … Read more
It means the value of data is None.
NoneType object has no attribute … means that you have an object that is None, and you’re trying to use an attribute of that object. In your case you’re doing q.get(…), so q must be None. Since q is the result of calling nse.get_quote(…), that function must have the possibility of returning None. You’ll need … Read more
remove doesn’t return anything. It modifies the existing list in-place. No assignment needed. Replace var = [‘p’, ‘s’, ‘c’, ‘x’, ‘d’].remove(‘d’) with var = [‘p’, ‘s’, ‘c’, ‘x’, ‘d’] var.remove(‘d’) Now var will have a value of [‘p’, ‘s’, ‘c’, ‘x’].
Because there are two print statements. First is inside function and second is outside function. When a function doesn’t return anything, it implicitly returns None. Use return statement at end of function to return value. e.g.: Return None. >>> def test1(): … print “In function.” … >>> a = test1() In function. >>> print a … Read more
NoneType means that instead of an instance of whatever Class or Object you think you’re working with, you’ve actually got None. That usually means that an assignment or function call up above failed or returned an unexpected result.
So how can I question a variable that is a NoneType? Use is operator, like this if variable is None: Why this works? Since None is the sole singleton object of NoneType in Python, we can use is operator to check if a variable has None in it or not. Quoting from is docs, The … Read more