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How do I get the number of elements in a list?
...turns 3.
Explanation
Everything in Python is an object, including lists. All objects have a header of some sort in the C implementation.
Lists and other similar builtin objects with a "size" in Python, in particular, have an attribute called ob_size, where the number of elements in the object is...
How do I correctly clean up a Python object?
...it close() statement is that you have to worry about people forgetting to call it at all or forgetting to place it in a finally block to prevent a resource leak when an exception occurs.
To use the with statement, create a class with the following methods:
def __enter__(self)
def __exit__(self...
How to disable GCC warnings for a few lines of code
...n GCC and Clang.
Consider the following Makefile
CPPFLAGS:=-std=c11 -W -Wall -pedantic -Werror
.PHONY: all
all: puts
for building the following puts.c source code
#include <stdio.h>
int main(int argc, const char *argv[])
{
while (*++argv) puts(*argv);
return 0;
}
It will not c...
How can you set class attributes from variable arguments (kwargs) in python
...riable number of arguments and then sets them as class attributes conditionally.
10 Answers
...
What does the “yield” keyword do?
... list, you can read its items one by one. Reading its items one by one is called iteration:
>>> mylist = [1, 2, 3]
>>> for i in mylist:
... print(i)
1
2
3
mylist is an iterable. When you use a list comprehension, you create a list, and so an iterable:
>>> mylist = [...
How do i find out what all symbols are exported from a shared object?
I have a shared object(dll). How do i find out what all symbols are exported from that?
9 Answers
...
How can you make a custom keyboard in Android?
...
First of all you will need a keyboard.xml file which will be placed in the res/xml folder (if the folder does not exist, created it).
<?xml version="1.0" encoding="utf-8"?>
<Keyboard xmlns:android="http://schemas.android.com...
What does a \ (backslash) do in PHP (5.3+)?
...a lot faster. However this only works when the functions are placed in the root namespace. See this discussion about this topic. So besides namespacing, the \ indirectly also affects code optimisation.
The following native functions benefit from this effect:
"array_slice"
"assert"
"boolval"
"call_...
What does if __name__ == “__main__”: do?
...ngs:
it sets a few special variables like __name__, and then
it executes all of the code found in the file.
Let's see how this works and how it relates to your question about the __name__ checks we always see in Python scripts.
Code Sample
Let's use a slightly different code sample to explore ho...
how to bypass Access-Control-Allow-Origin?
I'm doing a ajax call to my own server on a platform which they set prevent these ajax calls (but I need it to fetch the data from my server to display retrieved data from my server's database).
My ajax script is working , it can send the data over to my server's php script to allow it to process.
H...