大约有 40,000 项符合查询结果(耗时:0.0448秒) [XML]

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How to delete or add column in SQLITE?

...re are external tables referring to this table one must call PRAGMA foreign_keys=OFF. In this case, after doing this sequence one must call PRAGMA foreign_keys=ON in order to re-enable foreign keys. – PazO Apr 11 '18 at 9:12 ...
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Modifying the “Path to executable” of a windows service

...isplays output similar to: [SC] QueryServiceConfig SUCCESS SERVICE_NAME: ServiceName TYPE : 10 WIN32_OWN_PROCESS START_TYPE : 2 AUTO_START ERROR_CONTROL : 1 NORMAL BINARY_PATH_NAME : C:\Services\ServiceName LOAD_ORDER_GROUP : TAG ...
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What are the differences between NP, NP-Complete and NP-Hard?

...njunction (ANDs) of 3-clause disjunctions (ORs), statements of the form (x_v11 OR x_v21 OR x_v31) AND (x_v12 OR x_v22 OR x_v32) AND ... AND (x_v1n OR x_v2n OR x_v3n) where each x_vij is a boolean variable or the negation of a variable from a finite predefined list (x_1, x...
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find vs find_by vs where

...d are usually replaced with things like this: Model.all Model.first find_by is used as a helper when you're searching for information within a column, and it maps to such with naming conventions. For instance, if you have a column named name in your database, you'd use the following syntax: Mod...
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How to disable python warnings

...ee the warning, then it is possible to suppress the warning using the catch_warnings context manager: import warnings def fxn(): warnings.warn("deprecated", DeprecationWarning) with warnings.catch_warnings(): warnings.simplefilter("ignore") fxn() I don't condone it, but you could j...
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Docker - how can I copy a file from an image to a host?

... Actually, I use docker run --rm --entrypoint tar _image_ cC _img_directory_ . | tar xvC _host_directory_ – caligari Nov 30 '17 at 11:04 add a comment...
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How to make a class property? [duplicate]

...re's how I would do this: class ClassPropertyDescriptor(object): def __init__(self, fget, fset=None): self.fget = fget self.fset = fset def __get__(self, obj, klass=None): if klass is None: klass = type(obj) return self.fget.__get__(obj, klass)(...
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List all base classes in a hierarchy of given class?

...gt; >>> import inspect >>> inspect.getmro(B) (<class '__main__.B'>, <class '__main__.A'>, <type 'object'>) share | improve this answer | ...
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Best way to merge two maps and sum the values of same key?

...leads to arguably the shortest/cleanest solution: scala> import scalaz._ import scalaz._ scala> import Scalaz._ import Scalaz._ scala> val map1 = Map(1 -> 9 , 2 -> 20) map1: scala.collection.immutable.Map[Int,Int] = Map(1 -> 9, 2 -> 20) scala> val map2 = Map(1 -> 100, ...
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Shell脚本编程30分钟入门 - 更多技术 - 清泛网 - 专注C/C++及内核技术

Shell脚本编程30分钟入门linux_shell_30min_guides什么是Shell脚本示例看个例子吧:#! bin shcd ~mkdir shell_tutcd shell_tutfor ((i=0; i<10; i++)); do touch test_$i.txt... 什么是Shell脚本 示例 看个例子吧: #!/bin/sh cd ~ mkdir shell_tut cd shell_tut for (...