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How to pass a user defined argument in scrapy spider
...attributes:
class MySpider(scrapy.Spider):
name = 'myspider'
def __init__(self, category='', **kwargs):
self.start_urls = [f'http://www.example.com/{category}'] # py36
super().__init__(**kwargs) # python3
def parse(self, response)
self.log(self.domain) # sys...
Why are my CSS3 media queries not working?
...
In fact, have your css styles stacked in decreasing order from standard to smallest size. The rules still applies If you have your media queries all in the same file.
– Phil Andrews
Oct 14 '16 at 22:02
...
What is the difference between LL and LR parsing?
...ponds to Reverse Polish Notation. The difference between PN and RPN is the order of traversing the binary tree of the equation:
+ 1 * 2 3 // Polish (prefix) expression; pre-order traversal.
1 2 3 * + // Reverse Polish (postfix) expression; post-order traversal.
According to Haberman, this ill...
File Upload ASP.NET MVC 3.0
...Path.GetFileName(file.FileName);
// store the file inside ~/App_Data/uploads folder
var path = Path.Combine(Server.MapPath("~/App_Data/uploads"), fileName);
file.SaveAs(path);
}
// redirect back to the index action to show the form once again
...
Best way to compare 2 XML documents in Java
...gify and compare. So regardless of whitespace irregularities or attribute ordering, you can get regular, predictable comparisons of your documents.
This works especially well in IDEs that have dedicated visual String comparators, like Eclipse. You get a visual representation of the semantic differ...
How to process SIGTERM signal gracefully?
...n to use solution:
import signal
import time
class GracefulKiller:
kill_now = False
def __init__(self):
signal.signal(signal.SIGINT, self.exit_gracefully)
signal.signal(signal.SIGTERM, self.exit_gracefully)
def exit_gracefully(self,signum, frame):
self.kill_now = True
if __name...
When saving, how can you check if a field has changed?
...
Essentially, you want to override the __init__ method of models.Model so that you keep a copy of the original value. This makes it so that you don't have to do another DB lookup (which is always a good thing).
class Person(models.Model):
name = models.CharF...
How to import a module given its name as string?
...hat's pretty much how you do it.
For newer versions, see importlib.import_module for Python 2 and and Python 3.
You can use exec if you want to as well.
Or using __import__ you can import a list of modules by doing this:
>>> moduleNames = ['sys', 'os', 're', 'unittest']
>>> m...
hasNext in Python iterators?
...icult to write an adaptor that stores the result of next() and provides has_next() and move_next().
– avakar
Dec 24 '12 at 21:10
6
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Finding three elements in an array whose sum is closest to a given number
...e for that i, since we'd be summing the same elements, just in a different order. After that point, we try the next i and repeat.
Eventually, we'll either exhaust the useful possibilities, or we'll find the solution. You can see that this is O(n2) since we execute the outer loop O(n) times and we e...