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Naming convention for unique constraint
Naming conventions are important, and primary key and foreign key have commonly used and obvious conventions ( PK_Table and FK_Table_ReferencedTable , respectively). The IX_Table_Column naming for indexes is also fairly standard.
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Creating a new dictionary in Python
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Is there any difference between dict() and {}? Or do people just prefer one over the other?
– Matt
Mar 2 '12 at 17:13
53
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importing pyspark in python shell
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Turns out that the pyspark bin is LOADING python and automatically loading the correct library paths. Check out $SPARK_HOME/bin/pyspark :
# Add the PySpark classes to the Python path:
export PYTHONPATH=$SPARK_HOME/python/:$PYTHONPATH
I added this line to my .bashrc file...
Database design for a survey [closed]
...estions. For example: text fields for comments, multiple choice questions, and possibly questions that could contain more than one answer (i.e. check all that apply).
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How to wait for async method to complete?
... Very nice, thank you. I was scratching my head on a similar issue and the difference was to change void to Task just as you had said.
– Jeremy
Dec 11 '14 at 20:19
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What is the difference between square brackets and parentheses in a regex?
.../^[789]\d{9}$/
/^[7-9]\d{9}$/
The explanation:
(a|b|c) is a regex "OR" and means "a or b or c", although the presence of brackets, necessary for the OR, also captures the digit. To be strictly equivalent, you would code (?:7|8|9) to make it a non capturing group.
[abc] is a "character class" th...
Batch renaming files with Bash
... to remove their version numbers? I've been toying around with both expr and %% , to no avail.
10 Answers
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What is the best way to filter a Java Collection?
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Java 8 (2014) solves this problem using streams and lambdas in one line of code:
List<Person> beerDrinkers = persons.stream()
.filter(p -> p.getAge() > 16).collect(Collectors.toList());
Here's a tutorial.
Use Collection#removeIf to modify the collection...
Invoke a callback at the end of a transition
...itions.
Here's my own demo that changes the style of elements at the start and end of the transition.
From the documentation for transition.each([type],listener):
If type is specified, adds a listener for transition events, supporting both "start" and "end" events. The listener will be invoked...
How to fix the datetime2 out-of-range conversion error using DbContext and SetInitializer?
I'm using the DbContext and Code First APIs introduced with Entity Framework 4.1.
14 Answers
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