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List of lists changes reflected across sublists unexpectedly
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When you write [x]*3 you get, essentially, the list [x, x, x]. That is, a list with 3 references to the same x. When you then modify this single x it is visible via all three references to it:
x = [1] * 4
l = [x] * 3
print(f"id(x): {id(x)}")
# id(x): 1405608979...
Best way to strip punctuation from a string
...s working with the same datatype, but the approach in this answer works equally well for both, which is handy.
– Richard J
Jan 16 '15 at 9:35
38
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How to efficiently compare two unordered lists (not sets) in Python?
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For short lists, big-O analysis is usually irrelevant because the timings are dominated by constant factors. For the longer lists, I suspect something is wrong with your benchmarking. For 100 ints with 5 repeats each, I get: 127 usec for sorted and 42 for Count...
jQuery get value of selected radio button
...use you when you're used to seeing "" as the default value via the .val() call.
– xji
Jan 8 '18 at 22:30
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show 1 more comment
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How do I add custom field to Python log format string?
...LoggerAdapter so you don't have to pass the extra info with every logging call:
import logging
extra = {'app_name':'Super App'}
logger = logging.getLogger(__name__)
syslog = logging.StreamHandler()
formatter = logging.Formatter('%(asctime)s %(app_name)s : %(message)s')
syslog.setFormatter(formatte...
How do I configure different environments in Angular.js?
...strict";
angular.module("config", []).constant("ENV", "development");
Finally, I declare the dependency on whatever modules need it:
// the 'config' dependency is generated via grunt
var app = angular.module('myApp', [ 'config' ]);
Now my constants can be dependency injected where needed. E.g.,...
How to write header row with csv.DictWriter?
...ion "functionality", I'd prefer to code it myself; that way you can report ALL "extras" with the keys and values, not just the first extra key. What is a real nuisance with DictWriter is that if you've verified the keys yourself as each dict was being built, you need to remember to use extrasaction=...
JavaScript for detecting browser language preference [duplicate]
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I think the main problem here is that the browser settings don't actually affect the navigator.language property that is obtained via javascript.
What they do affect is the HTTP 'Accept-Language' header, but it appears this value is not available through javascript at all. (Probably why @and...
Python Unicode Encode Error
...80\x80abcd\xde\xb4'
>>> u.encode('ascii')
Traceback (most recent call last):
File "<stdin>", line 1, in ?
UnicodeEncodeError: 'ascii' codec can't encode character '\ua000' in position 0: ordinal not in range(128)
>>> u.encode('ascii', 'ignore')
'abcd'
>>> u.encode(...
How do synchronized static methods work in Java and can I use it for loading Hibernate entities?
If I have a util class with static methods that will call Hibernate functions to accomplish basic data access. I am wondering if making the method synchronized is the right approach to ensure thread-safety.
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