Note that best practice in Python 2.7 is to use new-style classes (not needed with Python 3), i.e. Also, there’s a difference between an ‘object’ and a ‘class’. To build a dictionary from an arbitrary object, it’s sufficient to use __dict__. Usually, you’ll declare your methods at class level and your attributes at instance level, so __dict__ should be fine. For … Read more
One trick is to solve this:
In Python versions 2.6 or earlier, you need to explicitly number the format fields: You can read about this in the docs: Changed in version 2.7: The positional argument specifiers can be omitted, so ‘{} {}’ is equivalent to ‘{0} {1}’.
If you are not satisfied with lists (because they can contain anything and take up too much memory) you can use efficient array of integers: See here If you need to initialize it,
This exception means that you’re trying to construct a dict from an iterable, and that iterable’s first element is not a sequence. As the docs explain, you can construct a dict two ways: From a mapping, or From an iterable of key-value pairs So, if you try to construct it from, say, a set of numbers: … … Read more
Just use append:
itertools often offers the fastest and most powerful solutions to this kind of problems, and is well worth getting intimately familiar with!-) Edit: as I mention in a comment, normal optimization efforts are focused on large inputs (the big-O approach) because it’s so much easier that it offers good returns on efforts. But sometimes (essentially for “tragically crucial … Read more
Your problem is that class B is not declared as a “new-style” class. Change it like so: and it will work. super() and all subclass/superclass stuff only works with new-style classes. I recommend you get in the habit of always typing that (object) on any class definition to make sure it is a new-style class. Old-style classes (also … Read more
Key point is to use os.makedirs in place of os.mkdir. It is recursive, i.e. it generates all intermediate directories. See http://docs.python.org/library/os.html Open the file in binary mode as you are storing binary (jpeg) data. In response to Edit 2, if img_alt sometimes has ‘/’ in it:
This is a bug in the readline compatibility in python, related to changes introduced in OSX10.9. This weekend, release candidates for Python2.7.6 and Python3.3.3 were released which fix this bug. The download links are below. http://python.org/download/releases/2.7.6/ http://python.org/download/releases/3.3.3/ Here’s the issue, quoting from Ned Deily, writing on the python-dev email list. On Tuesday, Apple released OS X … Read more