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What is the purpose of the -m switch?
...line of the Rationale section of PEP 338 says:
Python 2.4 adds the command line switch -m to allow modules to be located using the Python module namespace for execution as scripts. The motivating examples were standard library modules such as pdb and profile, and the Python 2.4 implementation is...
Split data frame string column into multiple columns
... stringr::str_split_fixed
library(stringr)
str_split_fixed(before$type, "_and_", 2)
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unique object identifier in javascript
I need to do some experiment and I need to know some kind of unique identifier for objects in javascript, so I can see if they are the same. I don't want to use equality operators, I need something like the id() function in python.
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How can I dynamically create derived classes from a base class
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This bit of code allows you to create new classes with dynamic
names and parameter names.
The parameter verification in __init__ just does not allow
unknown parameters, if you need other verifications, like
type, or that they are mandatory, just add the logic
there:
class BaseClass(object):...
Differences between lodash and underscore [closed]
...nsistent cross-environment iteration support for arrays, strings, objects, and arguments objects1. It has since become a superset of Underscore, providing more consistent API behavior, more features (like AMD support, deep clone, and deep merge), more thorough documentation and unit tests (tests whi...
vs2008编译boost详细步骤 - 开源 & Github - 清泛网 - 专注C/C++及内核技术
...工程， 配置工程属性
设置包含文件目录F:\Develop\BoostlibAndDll\include\boost-1_37\boost
设置引用文件目录:F:\Develop\BoostlibAndDll\lib
完成后，可以使用。
【三、介绍Bjam使用】
Usage:
Bjam [options] [properties] [install|stage]
instal...
Why does the expression 0 < 0 == 0 return False in Python?
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I believe Python has special case handling for sequences of relational operators to make range comparisons easy to express. It's much nicer to be able to say 0 < x <= 5 than to say (0 < x) and (x <= 5).
These are called chained comparisons. And th...
python NameError: global name '__file__' is not defined
...ractive shell.
Python Shell doesn't detect current file path in __file__ and it's related to your filepath in which you added this line
So you should write this line os.path.join(os.path.dirname(__file__)) in file.py. and then run python file.py, It works because it takes your filepath.
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Why is “if not someobj:” better than “if someobj == None:” in Python?
... the object has a __nonzero__ special method (as do numeric built-ins, int and float), it calls this method. It must either return a bool value which is then directly used, or an int value that is considered False if equal to zero.
Otherwise, if the object has a __len__ special method (as do contain...
Python constructors and __init__
Why are constructors indeed called "Constructors"? What is their purpose and how are they different from methods in a class?
...