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In Java, what does NaN mean?
...fined (in arithmetics)"... Its not! its actually i and some languages like python deal very well with it... It may be not the case in java thou
– Rafael T
Feb 10 '14 at 18:40
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总结const_cast、static_cast、dynamic_cast、reinterpret_cast - C/C++ - ...
...父类和子类指针或应用的互相转化;
static_cast一般是普通数据类型(如int m=static_cast<int>(3.14));
reinterpret_cast很像c的一般类型转换操作
const_cast是把cosnt或volatile属性去掉
介绍
大多程序员在学C++前都学过C，并且习惯于C风格...
Can I “multiply” a string (in C#)?
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I don't think it's elegant at all. In python the code to do this is: snip * multiplier (It's not horrible.. but neither is it beautiful).
– demented hedgehog
Jun 2 '15 at 2:56
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How to exit from PostgreSQL command line utility: psql
...tion to always working in pgsql it'll work in most your other unix shells (python, mysql, etc). If you always do things the "standard" way in 'nix your brain will be less cluttered with trivia.
– hobs
Nov 7 '13 at 22:10
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How do you create different variable names while in a loop? [duplicate]
...(cat_4)
8
Here I am taking advantage of the handy f string formatting in Python 3.6+
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Should I use != or for not equal in T-SQL?
... its existence in every C-influenced language I have used, and because the Python documentation says: "The forms <> and != are equivalent; for consistency with C, != is preferred; where != is mentioned below <> is also accepted. The <> spelling is considered obsolescent." But SQL i...
How to query MongoDB with “like”?
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In
PyMongo using Python
Mongoose using Node.js
Jongo, using Java
mgo, using Go
you can do:
db.users.find({'name': {'$regex': 'sometext'}})
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How to add pandas data to an existing csv file?
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You can specify a python write mode in the pandas to_csv function. For append it is 'a'.
In your case:
df.to_csv('my_csv.csv', mode='a', header=False)
The default mode is 'w'.
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In Django, how does one filter a QuerySet with dynamic field lookups?
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Python's argument expansion may be used to solve this problem:
kwargs = {
'{0}__{1}'.format('name', 'startswith'): 'A',
'{0}__{1}'.format('name', 'endswith'): 'Z'
}
Person.objects.filter(**kwargs)
This is a very c...
finding and replacing elements in a list
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This is a bad and very un-pythonic solution. Consider using list comprehension.
– AdHominem
Dec 31 '16 at 11:56
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