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How to remove from a map while iterating it?
...begin(); it != m.cend() /* not hoisted */; /* no increment */)
{
if (must_delete)
{
m.erase(it++); // or "it = m.erase(it)" since C++11
}
else
{
++it;
}
}
Note that we really want an ordinary for loop here, since we are modifying the container itself. The range-based loop sh...
Can someone explain in simple terms to me what a directed acyclic graph is?
...Hence B depends on A or in better terms A has an edge directed to B. So in order to reach Node B you have to visit Node A. It will soon be clear that after adding all the subjects with its pre-requisites into a graph, it will turn out to be a Directed Acyclic Graph.
If there was a cycle then yo...
Why do we always prefer using parameters in SQL statements?
... the SQL statement is not going to be the same
– marc_s
Sep 21 '11 at 20:57
1
that means sql inje...
What is the maximum recursion depth in Python, and how to increase it?
...mple context manager like this:
import sys
class recursionlimit:
def __init__(self, limit):
self.limit = limit
self.old_limit = sys.getrecursionlimit()
def __enter__(self):
sys.setrecursionlimit(self.limit)
def __exit__(self, type, value, tb):
sys.setr...
Pandas - How to flatten a hierarchical index in columns
... would be to set the columns to the top level:
df.columns = df.columns.get_level_values(0)
Note: if the to level has a name you can also access it by this, rather than 0.
.
If you want to combine/join your MultiIndex into one Index (assuming you have just string entries in your columns) you cou...
How is a CRC32 checksum calculated?
... 1100001010 = Quotient (nobody cares about the quotient)
_______________
10011 ) 11010110110000 = Augmented message (1101011011 + 0000)
=Poly 10011,,.,,....
-----,,.,,....
10011,.,,....
10011,.,,....
-----,.,,....
00001.,,....
...
How can I check for Python version in a program that uses new language features?
...oesn't have ternary
Also, with is available in Python 2.5, just add from __future__ import with_statement.
EDIT: to get control early enough, you could split it into different .py files and check compatibility in the main file before importing (e.g. in __init__.py in a package):
# __init__.py
#...
What is an 'endpoint' in Flask?
...c view is defined like this:
@app.route('/greeting/<name>')
def give_greeting(name):
return 'Hello, {0}!'.format(name)
Note that the function you referred to (add_url_rule) achieves the same goal, just without using the decorator notation. Therefore, the following is the same:
# No "ro...
while (1) vs. while(True) — Why is there a difference (in python 2 bytecode)?
...oes.
Here's 2.7:
>>> dis.dis('True == 1')
1 0 LOAD_GLOBAL 0 (True)
3 LOAD_CONST 1 (1)
6 COMPARE_OP 2 (==)
9 RETURN_VALUE
>>> dis.dis('True == 1')
1 0 LOAD_GLOBAL ...
如何获取IE (控件)的所有链接（包括Frameset, iframe） - 其他 - 清泛IT社...
来源：新浪博客
IE 顶层 body 节点通过IHTMLElement->get_all 方法无法获取iframe 里面的节点列表：
CComPtr<IHTMLElement> body;
...
CComPtr<IDispatch> spDispCollection;
body->get_all(&spDispCollection);所以要获取iframe/frame(frameset) 里面的节...