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How to take the first N items from a generator or list in Python? [duplicate]
...imple syntax: array[start:stop:step]
You can omit any parameter. These are all valid: array[start:], array[:stop], array[::step]
Slicing a generator
import itertools
top5 = itertools.islice(my_list, 5) # grab the first five elements
You can't slice a generator directly in Python. itertools.i...
Proper use of beginBackgroundTaskWithExpirationHandler
...l need to wrap it in a background task. It's also very important that you call endBackgroundTask when you're finished - otherwise the app will be killed after its allotted time has expired.
Mine tend look something like this:
- (void) doUpdate
{
dispatch_async(dispatch_get_global_queue(DISPAT...
Add data annotations to a class generated by entity framework
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The generated class ItemRequest will always be a partial class. This allows you to write a second partial class which is marked with the necessary data annotations. In your case the partial class ItemRequest would look like this:
using System.ComponentModel;
using System.ComponentModel.DataAn...
How to print to stderr in Python?
...to make your code Python3-ready. I guess this could be why many people actually like it!
– MarcH
Nov 18 '14 at 19:00
18
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Specify sudo password for Ansible
...
For example, you might have a playbook something like this:
- hosts: all
vars_files:
- secret
tasks:
- name: Do something as sudo
service: name=nginx state=restarted
sudo: yes
Here we are including a file called secret which will contain our sudo password.
We will...
Why does calling a function in the Node.js REPL with )( work?
Why is it possible to call function in JavaScript like this, tested with node.js:
3 Answers
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Mail multipart/alternative vs multipart/mixed
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I hit this challenge today and I found these answers useful but not quite explicit enough for me.
Edit: Just found the Apache Commons Email that wraps this up nicely, meaning you don't need to know below.
If your requirement is an emai...
How can I perform a str_replace in JavaScript, replacing text in JavaScript?
...erf, you can have different levels of efficiency for creating a regex, but all of them are significantly slower than a simple string replace. The regex is slower because:
Fixed-string matches don't have backtracking, compilation steps, ranges, character classes, or a host of other features that ...
Insert into … values ( SELECT … FROM … )
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is it Necessary that we insert into all columns of the table
– maheshmnj
Feb 24 at 7:22
1
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Make sure that the controller has a parameterless public constructor error
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What's happening is that you're bitten by this problem. Basically, what happened is that you didn't register your controllers explicitly in your container. Unity tries to resolve unregistered concrete types for you, but because it can't resolve it (caused by an error in your configurat...