The package Python for.NET and the Python Implementation IronPython now work the same way. Example for a C# DLL MyDll.dll: import clr clr.AddReference(‘MyDll’) from MyNamespace import MyClass my_instance = MyClass() See this post for more details.
The difference is in the implementation of the int type. Python 3.x uses the arbitrary-sized integer type (long in 2.x) exclusively, while in Python 2.x for values up to sys.maxint a simpler int type is used that uses a simple C long under the hood. Once you limit your loops to long integers, Python 3.x … Read more
It’s a combination of Boyer-Moore and Horspool. You can view the C code here: Fast search/count implementation, based on a mix between Boyer-Moore and Horspool, with a few more bells and whistles on the top. For some more background, see: https://web.archive.org/web/20201107074620/http://effbot.org/zone/stringlib.htm. From the link above: When designing the new algorithm, I used the following constraints: … Read more
Sets and dicts are optimized for different use-cases. The primary use of a set is fast membership testing, which is order agnostic. For dicts, cost of the lookup is the most critical operation, and the key is more likely to be present. With sets, the presence or absence of an element is not known in … Read more
-1 is a reserved value at the C level of CPython which prevents hash functions from being able to produce a hash value of -1. As noted by DSM, the same is not true in IronPython and PyPy where hash(-1) != hash(-2). See this Quora answer: If you write a type in a C extension … Read more
How does Python detect & free circular memory references before making use of the gc module? It doesn’t. The gc exists only to detect and free circular references. Non-circular references are handled through refcounting. Now, to see how gc determines the set of objects referenced by any given object, take a look at the gc_get_references … Read more
No, sets are still unordered. You can verify this just by displaying a set that should have a “well-defined hash order”1 to make sure we don’t accidentally get a set that looks ordered but actually isn’t: >>> a_set = {3,2,1} >>> a_set {1, 2, 3} >>> list(a_set) [1, 2, 3] If it were ordered you … Read more
This has only been tested on Windows: You can do the following: import os os.startfile(“C:/Users/TestFile.txt”, “print”) This will start the file, in its default opener, with the verb ‘print’, which will print to your default printer.Only requires the os module which comes with the standard library
TL:DR: a slice compare is some Python overhead + a highly-optimized memcmp (unless there’s UTF-8 processing?). Ideally, use slice compares to find the first mismatch to within less than 128 bytes or something, then loop a char at a time. Or if it’s an option and the problem is important, make a modified copy of … Read more
why does it get 12 more bytes for 2⁶³ compared too 2⁶³ – 1 and not just one? On an LP64 system1, a Python 2 int consists of exactly three pointer-sized pieces: type pointer reference count actual value, a C long int That’s 24 bytes in total. On the other hand, a Python long consists … Read more