There are at least 6 (!) ways to clone an array: loop slice Array.from() concat spread operator (FASTEST) map A.map(function(e){return e;}); There has been a huuuge BENCHMARKS thread, providing following information: for blink browsers slice() is the fastest method, concat() is a bit slower, and while loop is 2.4x slower. for other browsers while loop … Read more
Breadth vs Depth; think in terms of a tree of references with your object as the root node. Shallow: The variables A and B refer to different areas of memory, when B is assigned to A the two variables refer to the same area of memory. Later modifications to the contents of either are instantly … Read more
Create a copy constructor: class DummyBean { private String dummy; public DummyBean(DummyBean another) { this.dummy = another.dummy; // you can access } } Every object has also a clone method which can be used to copy the object, but don’t use it. It’s way too easy to create a class and do improper clone method. … Read more
new_list = my_list doesn’t actually create a second list. The assignment just copies the reference to the list, not the actual list, so both new_list and my_list refer to the same list after the assignment. To actually copy the list, you have several options: You can use the builtin list.copy() method (available since Python 3.3): … Read more
scp -r user@your.server.example.com:/path/to/foo /home/user/Desktop/ By not including the trailing “https://stackoverflow.com/” at the end of foo, you will copy the directory itself (including contents), rather than only the contents of the directory. From man scp (See online manual) -r Recursively copy entire directories
shutil has many methods you can use. One of which is: import shutil shutil.copyfile(src, dst) # 2nd option shutil.copy(src, dst) # dst can be a folder; use shutil.copy2() to preserve timestamp Copy the contents of the file named src to a file named dst. Both src and dst need to be the entire filename of … Read more