In the first situation, Num2 is extending the class Num and since you are not redefining the special method named __init__() in Num2, it gets inherited from Num. When a class defines an __init__() method, class instantiation automatically invokes __init__() for the newly-created class instance. In the second situation, since you are redefining __init__() in Num2 you need to explicitly call the one in the super class (Num) if you want … Read more
You can find information about Python audio here: http://wiki.python.org/moin/Audio/ It doesn’t look like it can play .mp3 files without external libraries. You could either convert your .mp3 file to a .wav or other format, or use a library like PyMedia.
money is a file object, not the content of the file. To get the content, you have to read the file. If the entire file contains just that one number, then read() is all you need. Otherwise you might want to use readline() to read a single line or even try the csv module for … Read more
If all you care about are digits, you can use the str.maketrans() and str.translate() methods: Which will output: Note that this won’t work in Python 2 – see Python 2 maketrans() function doesn’t work with Unicode for an explanation of why that’s the case, and how to work around it.
that doesn’t work. If you specify positions, you have to do it through the end: In your case, best is to leave python treat that automatically:
Yes, the 0-argument syntax is specific to Python 3, see What’s New in Python 3.0 and PEP 3135 — New Super. In Python 2 and code that must be cross-version compatible, just stick to passing in the class object and instance explicitly. Yes, there are “backports” available that make a no-argument version of super() work … Read more
I simplified the test a bit – if all(x%y instead of if not any(not x%y I also limited y’s range; there is no point in testing for divisors > sqrt(x). So max(x) == 100 implies max(y) == 10. For x <= 10, y must also be < x. Instead of generating pairs of primes and … Read more
I never really understood the “Language X for Language Y developers” approach. When I go looking to learn Language X I want to learn how to program in it the way that Language X programmers do, not the way Language Y programmers do. I want to learn the features, idioms, etc. that are unique to … Read more
What causes the SystemError in this line of code cv2.line(output, point1, point2, (0,0,255), 5)?
Use not