How to avoid "pointing to same object" while creating nested dictionary using zip and map? Question: I would like to avoid pointing to the same object in the below code. Please look at output and desired output stated below. Code: import random prototype = [{‘uniqueDict’: list()}] def mapme(somekey): global aa aa = [random.randint(0, 5), random.randint(6, …
Python: Need help solving this problem using two pointers method Question: I’m currently practicing coding problems and found this problem called "Successful Pairs of Spells and Potions", the problem describtion is as follows; You are given two positive integer arrays spells and potions, of length n and m respectively, where spells[i] represents the strength of …
Allocation of Memory with python to pass to dll Question: I got a dll which expects a memory pointer to a C Type Byte Array. The dll will read and modify the Array and will also put some extra data at the end of the array. How do I allocate 1MB memory as C Type …
How can i cast a double pointer ctype to numpy array? Question: Hey I got this code which i’m using to cast numpy 2d array to ctype double pointer. import ctypes as ct import numpy as np arr = np.empty([500, 500], dtype=np.uint8) UI8Ptr = ct.POINTER(ct.c_uint8) UI8PtrPtr = ct.POINTER(UI8Ptr) ct_arr = np.ctypeslib.as_ctypes(arr) UI8PtrArr = UI8Ptr * …
When does a pointer to a linked list change the actual list? Question: I have a singly-linked-list, L, and create a pointer to this list P. It seems like sometimes modifying P changes the actual list, while other times modifying P does nothing to the actual list L and only changes what P is pointing …
How to pass a 2d array from Python to C? Question: I’m trying to pass a 2d array from Python to C, using ctypes. The array dtype is uint16. I wrote a simple code just to understand how it works: C: #include <stdint.h> __declspec(dllexport) uint16_t Test(uint16_t **arr) { return (arr[5][5]); } Python: import numpy as …
Explanation about dummy nodes and pointers in linked lists Question: I have the following class for a list node: def __init__(self, x): self.val = x self.next = None If I initialize the lists l and r as follows: l = ListNode(1) l.next = ListNode(4) l.next.next = ListNode(5) r = ListNode(1) r.next = ListNode(3) r.next.next = …
How to make a list of functions in python? Question: I tried to achieve something like this list1 = [lambda x: x+0, lambda x: x+1] by doing this list2 = [lambda x: x+n for n in range(2)] But it doesn’t work! (Why not?) How do I create a list of functions programmatically? Asked By: Ziofil …
Storing unsafe C derivative of temporary Python reference error in Cython Question: I was writing code to store a (potentially) very large integer value into an array of chars referenced by a pointer. My code looks like this: cdef class Variable: cdef unsigned int Length cdef char * Array def __cinit__(self, var, length): self.Length = …
Don't understand Python's csv.reader object Question: I’ve come across a behavior in python’s built-in csv module that I’ve never noticed before. Typically, when I read in a csv, it’s following the doc’s pretty much verbatim, using ‘with’ to open the file then looping over the reader object with a ‘for’ loop. However, I recently tried …
