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What's the difference between lists and tuples?
...cture, lists have order.
Using this distinction makes code more explicit and understandable.
One example would be pairs of page and line number to reference locations in a book, e.g.:
my_location = (42, 11) # page number, line number
You can then use this as a key in a dictionary to store not...
How to find out what group a given user has?
In Unix/Linux, how do you find out what group a given user is in via command line?
5 Answers
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SQLAlchemy: how to filter date field?
...our filter is excluding all records: you should change the <= for >= and vice versa:
qry = DBSession.query(User).filter(
and_(User.birthday <= '1988-01-17', User.birthday >= '1985-01-17'))
# or same:
qry = DBSession.query(User).filter(User.birthday <= '1988-01-17').\
...
Check if a Windows service exists and delete in PowerShell
...$ServiceName.
# Returns a boolean $True or $False.
Function ServiceExists([string] $ServiceName) {
[bool] $Return = $False
# If you use just "Get-Service $ServiceName", it will return an error if
# the service didn't exist. Trick Get-Service to return an array of
# Services, but o...
Clear terminal in Python [duplicate]
...afe from injections because there is no user input involved there. All the strings that could be passed to os.system are fixed.
– poke
Mar 26 '16 at 0:10
1
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public friend swap member function
...ction is just noise. A member function allows for e.g. std::vector<std::string>().swap(someVecWithData);, which isn't possible with a swap free function because both arguments are passed by non-const reference.
– ildjarn
Apr 18 '11 at 1:34
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Getting an object from an NSSet
...containsObject to test for membership, use anyObject to get a member (not random), or convert it to an array (in no particular order) with allObjects.
A set is appropriate when you don't want duplicates, don't care about order, and want fast membership testing.
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How to keep Maven profiles which are activeByDefault active even if another profile gets activated?
...
One trick is to avoid activeByDefault, and instead activate the profile by the absence of a property, eg:
<profiles>
<profile>
<id>firstProfile</id>
<activation>
<property>
<name>!skipFirstProfile&...
Select distinct values from a table field
...uery, not even the default ordering, call order_by() with no parameters.
and distinct() in the note where it discusses issues with using distinct() with ordering.
To query your DB, you just have to call:
models.Shop.objects.order_by().values('city').distinct()
It returns a dictionnary
or
mod...
What does 'low in coupling and high in cohesion' mean
...: An implementation of List interface should not have operation related to String. String class should have methods, fields which is relevant for String and similarly, the implementation of List should have corresponding things.
Hope that helps.
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