Summary The method in question returns the special value None, which is the unique instance of the NoneType type. It updates the object as a side effect, and does not return that object. Since x.y() returns None, x = x.y() causes x to become None, and x.y().z() fails because None does not have the specified … Read more
intprices.sort() is sorting in place and returns None, while sorted( intprices ) creates a brand new sorted list from your list and returns it. In your case, since you’re not wanting to keep intprices around in its original form simply doing intprices.sort() without reassigning will solve your issue.
The print() function returns None. You are trying to index None. You can not, because ‘NoneType’ object is not subscriptable. Put the [0] inside the brackets. Now you’re printing everything, and not just the first term.
You want to pass the function object hi to your loop() function, not the result of a call to hi() (which is None since hi() doesn’t return anything). So try this: >>> loop(hi, 5) hi hi hi hi hi Perhaps this will help you understand better: >>> print hi() hi None >>> print hi <function … Read more
>>> l = [1, 3, 2, 5, 4, None, 7] >>> sorted(l, key=lambda x: (x is None, x)) [1, 2, 3, 4, 5, 7, None] This constructs a tuple for each element in the list, if the value is None the tuple with be (True, None), if the value is anything else it will be … Read more
The documentation suggests that what you want is not possible: To make it as easy as possible to interface with modules which implement the DB API, the value None is written as the empty string. This is in the documentation for the writer class, suggesting it is true for all dialects and is an intrinsic … Read more
Overview In general, there are two kinds of queries offered by BeautifulSoup: ones that look for a single specific element (tag, attribute, text etc.), and those which look for each element that meets the requirements. For the latter group – the ones like .find_all that can give multiple results – the return value will be … Read more
>>> L = [0, 23, 234, 89, None, 0, 35, 9] >>> [x for x in L if x is not None] [0, 23, 234, 89, 0, 35, 9] Just for fun, here’s how you can adapt filter to do this without using a lambda, (I wouldn’t recommend this code – it’s just for scientific … Read more
Functions always return something (at least None, when no return-statement was reached during execution and the end of the function is reached). Another case is when they are interrupted by exceptions. In this case exception handling will “dominate over the stack” and you will return to the appropriate except or get some nasty error 🙂 … Read more
widget is stored as None because geometry manager methods grid, pack, place return None, and thus they should be called on a separate line than the line that creates an instance of the widget as in: widget = … widget.grid(..) or: widget = … widget.pack(..) or: widget = … widget.place(..) And for the 2nd code … Read more