大约有 46,000 项符合查询结果(耗时:0.0476秒) [XML]

https://stackoverflow.com/ques... 

Why do people say there is modulo bias when using a random number generator?

...AND_MAX is 10 and I decide to generate a random number between 0 and 2 by calling rand()%3. However, rand()%3 does not produce the numbers between 0 and 2 with equal probability! When rand() returns 0, 3, 6, or 9, rand()%3 == 0. Therefore, P(0) = 4/11 When rand() returns 1, 4, 7, or 10, rand()%3 ...
https://stackoverflow.com/ques... 

How to set environment variables in Python?

I need to set some environment variables in the Python script and I want all the other scripts that are called from Python to see the environment variables' set. ...
https://stackoverflow.com/ques... 

Elegant setup of Python logging in Django

...nowhere else. You can either use a configuration file or do it programmatically step-by-step - it just depends on your requirements. The key thing is that I usually add the handlers I want to the root logger, using levels and sometimes logging.Filters to get the events I want to the appropriate file...
https://stackoverflow.com/ques... 

Django 1.7 - makemigrations not detecting changes

... may happen due to the following reasons: You did not add the app in INSTALLED_APPS list in settings.py (You have to add either the app name or the dotted path to the subclass of AppConfig in apps.py in the app folder, depending on the version of django you are using). Refer documentation: INST...
https://stackoverflow.com/ques... 

Assignment inside lambda expression in Python

I have a list of objects and I want to remove all objects that are empty except for one, using filter and a lambda expression. ...
https://stackoverflow.com/ques... 

How to append contents of multiple files into one file

... should be >> right ? and also why is there a newline before all the text in my 0.txt file ? – Steam Aug 2 '13 at 0:00 2 ...
https://stackoverflow.com/ques... 

Python Dictionary Comprehension

...>> print d {0: 0, 1: 1, 2: 4, 3: 9, 4: 16} If you want to set them all to True: >>> d = {n: True for n in range(5)} >>> print d {0: True, 1: True, 2: True, 3: True, 4: True} What you seem to be asking for is a way to set multiple keys at once on an existing dictionary. ...
https://stackoverflow.com/ques... 

Why do we always prefer using parameters in SQL statements?

...uld be SELECT empSalary from employee where salary = 0 or 1=1 whereby all empSalaries would be returned. Further, a user could perform far worse commands against your database, including deleting it If they wrote 0; Drop Table employee: SELECT empSalary from employee where salary = 0; Drop Ta...
https://stackoverflow.com/ques... 

Adding information to an exception?

...essage + ' happens at %s' % arg1) bar('arg1') Traceback (most recent call last): File "test.py", line 13, in <module> bar('arg1') File "test.py", line 11, in bar raise type(e)(e.message + ' happens at %s' % arg1) IOError: Stuff happens at arg1 Update 1 Here's a slight modif...
https://stackoverflow.com/ques... 

Remove an item from array using UnderscoreJS

...r question). Then you would only iterate over array once instead of potentially twice like here. If you want to modify the array in-place, you have to use .splice. This is also shown in the other question and undescore doesn't seem to provide any useful function for that. ...