I am trying to run this code in Python 3.7: import web urls = ('/', 'index') if __name__ == "__main__": app = web.application(urls, globals()) app.run() But it gives me this error ev...

i have a generator where i would like to add an initial and final value to the actual content, it's something like this: # any generic queue where i would like to get something from q = Queue() d...

Why in the example function terminates: def func(iterable): while True: val = next(iterable) yield val but if I take off yield statement function will raise StopIteration exception? EDIT: So...

I'm reading the documentation for Python 3 here: If a generator code directly or indirectly raises StopIteration, it is converted into a RuntimeError (retaining the StopIteration as the new exce...

I am not able to clarify my self over the use of next() in python(3). I have a data : chr pos ms01e_PI ms01e_PG_al ms02g_PI ms02g_PG_al ms03g_PI ms03g_PG_al ms04h_PI ms04h_PG_al 2 15881989 4 C|C ...

Could someone help me understand what PEP479 is about? I was reading the doc and couldn't get my head around it. The abstract says: This PEP proposes a change to generators: when StopIteration ...

I'm curious about the difference between using raise StopIteration and a return statement in generators. For example, is there any difference between these two functions? def my_generator0(n): f...

There are several ways to break out of a few nested loops They are: 1) to use break-continue for x in xrange(10): for y in xrange(10): print x*y if x*y > 50: break else: continue # only...

I have a line that is pulling in variables from multiple lists and I want it to avoid the StopIteration error that comes up so that it can move onto the next line. At the moment I am using the brea...

In this piece of code, why does using for result in no StopIteration or is the for loop trapping all exceptions and then silently exiting? In which case, why do we have the extraneous return?? Or i...

I am trying to iterate through a list, and I need to perform specific operation when and only when the iteration reached the end of the list, see example below: data = [1, 2, 3] data_iter = data....

What would be the nice way to return something from an iterator one last time when it's exhausted. I'm using a flag, but this is rather ugly: class Example(): def __iter__(self): self.lst = [1,...

I am using generators to perform searches in lists like this simple example: >>> a = [1,2,3,4] >>> (i for i, v in enumerate(a) if v == 4).next() 3 (Just to frame the example a ...

I'd like to read at most 20 lines from a csv file: rows = [csvreader.next() for i in range(20)] Works fine if the file has 20 or more rows, fails with a StopIteration exception otherwise. Is th...