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What is the difference between save and insert in Mongo DB?
...is essentially the same.
save behaves differently if it is passed with an "_id" parameter.
For save, If the document contains _id, it will upsert querying the collection on the _id field, If not, it will insert.
If a document does not exist with the specified _id value, the save() method performs a...
How to get the parent dir location
...bspath doesn't validate anything, so if we're already appending strings to __file__ there's no need to bother with dirname or joining or any of that. Just treat __file__ as a directory and start climbing:
# climb to __file__'s parent's parent:
os.path.abspath(__file__ + "/../../")
That's far less...
How to len(generator()) [duplicate]
...e advantages over functions that return lists. However, you could len(list_returning_function()) . Is there a way to len(generator_function()) ?
...
Proper way to return JSON using node or Express
...ing to send a json file you can use streams
var usersFilePath = path.join(__dirname, 'users.min.json');
apiRouter.get('/users', function(req, res){
var readable = fs.createReadStream(usersFilePath);
readable.pipe(res);
});
...
How do I pass extra arguments to a Python decorator?
... it needs to return another function which is the actual decorator:
def my_decorator(param):
def actual_decorator(func):
print("Decorating function {}, with parameter {}".format(func.__name__, param))
return function_wrapper(func) # assume we defined a wrapper somewhere
ret...
Can I serve multiple clients using just Flask app.run() as standalone?
...onal keyword arguments (**options) that it forwards to werkzeug.serving.run_simple - two of those arguments are threaded (a boolean) and processes (which you can set to a number greater than one to have werkzeug spawn more than one process to handle requests).
threaded defaults to True as of Flask ...
How to find list of possible words from a letter matrix [Boggle Solver]
...n Python that I just coded up:
#!/usr/bin/python
class TrieNode:
def __init__(self, parent, value):
self.parent = parent
self.children = [None] * 26
self.isWord = False
if parent is not None:
parent.children[ord(value) - 97] = self
def MakeTrie(dict...
What does the restrict keyword mean in C++?
...h the time.
Edit
I also found that IBM's AIX C/C++ compiler supports the __restrict__ keyword.
g++ also seems to support this as the following program compiles cleanly on g++:
#include <stdio.h>
int foo(int * __restrict__ a, int * __restrict__ b) {
return *a + *b;
}
int main(void) {
...
How to get the original value of an attribute in Rails
...
Before rails 5.1
Appending _was to your attribute will give you the previous value.
For rails 5.1+
Copied from Lucas Andrade's answer below: https://stackoverflow.com/a/50973808/9359123
Appending _was is deprecated in rails 5.1, now you should ap...
How to convert list of tuples to multiple lists?
...
xs, ys = [x for x, y in zs], [y for x, y in zs]
return xs, ys
if __name__ == '__main__':
from timeit import timeit
setup_string='''\
N = 2000000
xs = list(range(1, N))
ys = list(range(N+1, N*2))
zs = list(zip(xs, ys))
from __main__ import t1, t2, t3
'''
print(f'zip:\t\t{timeit(...