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The attribute tools:ignore can be used in xml files to dismiss lint warnings. BUT dismissing lint warnings with this technique is most of the time the wrong way to proceed. A lint warning must be understood and fixed... it can be ignored if and only if you have a full understanding of it's meaning...

Extensions can contain convenience initializers. For example, a failable initializer for Int that accepts a NSString: extension Int { init?(_ string: NSString) { self.init(string as String) // delegate to the existing Int.init(String) initializer } } let str1: NSString = &qu...

In addition to .done, .fail and .always promise callbacks, which are triggered based on whether the request was successful or not, there is the option to trigger a function when a specific HTTP Status Code is returned from the server. This can be done using the statusCode parameter. $.ajax({ t...

Extensions are used to extend the functionality of existing types in Swift. Extensions can add subscripts, functions, initializers, and computed properties. They can also make types conform to protocols. Suppose you want to be able to compute the factorial of an Int. You can add a computed property...

CREATE INDEX ix_cars_employee_id ON Cars (EmployeeId); This will create an index for the column EmployeeId in the table Cars. This index will improve the speed of queries asking the server to sort or select by values in EmployeeId, such as the following: SELECT * FROM Cars WHERE EmployeeId = 1 ...

Exponentiation can be used by using the builtin pow-function or the ** operator: 2 ** 3 # 8 pow(2, 3) # 8 For most (all in Python 2.x) arithmetic operations the result's type will be that of the wider operand. This is not true for **; the following cases are exceptions from this rule: B...

The math-module contains another math.pow() function. The difference to the builtin pow()-function or ** operator is that the result is always a float: import math math.pow(2, 2) # 4.0 math.pow(-2., 2) # 4.0 Which excludes computations with complex inputs: math.pow(2, 2+0j) TypeErro...

Both the math and cmath-module contain the Euler number: e and using it with the builtin pow()-function or **-operator works mostly like math.exp(): import math math.e ** 2 # 7.3890560989306495 math.exp(2) # 7.38905609893065 import cmath cmath.e ** 2 # 7.3890560989306495 cmath.exp(2) # (...

The math module contains the expm1()-function that can compute the expression math.e ** x - 1 for very small x with higher precision than math.exp(x) or cmath.exp(x) would allow: import math print(math.e ** 1e-3 - 1) # 0.0010005001667083846 print(math.exp(1e-3) - 1) # 0.0010005001667083846 p...

Supposing you have a class that stores purely integer values: class Integer(object): def __init__(self, value): self.value = int(value) # Cast to an integer def __repr__(self): return '{cls}({val})'.format(cls=self.__class__.__name__, ...

You can have multiple versions of Xcode installed at the same time (including beta versions). Simply rename the application in Finder to avoid conflicts. Note: Installing Xcode from the App Store will tend to overwrite an existing version on your machine. You can also install Xcode from a direct ...

You can list existing git aliases using --get-regexp: $ git config --get-regexp '^alias\.' Searching aliases To search aliases, add the following to your .gitconfig under [alias]: aliases = !git config --list | grep ^alias\\. | cut -c 7- | grep -Ei --color \"$1\" "#" The...

String also have an index method but also more advanced options and the additional str.find. For both of these there is a complementary reversed method. astring = 'Hello on StackOverflow' astring.index('o') # 4 astring.rindex('o') # 20 astring.find('o') # 4 astring.rfind('o') # 20 The ...

list and tuple have an index-method to get the position of the element: alist = [10, 16, 26, 5, 2, 19, 105, 26] # search for 16 in the list alist.index(16) # 1 alist[1] # 16 alist.index(15) ValueError: 15 is not in list But only returns the position of the first found element: ...

Sorted sequences allow the use of faster searching algorithms: bisect.bisect_left()1: import bisect def index_sorted(sorted_seq, value): """Locate the leftmost value exactly equal to x or raise a ValueError""" i = bisect.bisect_left(sorted_seq, value) ...

from itertools import imap from future_builtins import map as fmap # Different name to highlight differences image = [[1, 2, 3], [4, 5, 6], [7, 8, 9]] list(map(None, *image)) # Out: [(1, 4, 7), (2, 5, 8), (3, 6, 9)] list(fmap(None, *image)) # Out: [(1, 4, 7), (2, 5, 8),...

Abbreviated from https://blogs.dropbox.com/developers/2013/07/using-oauth-2-0-with-the-core-api/: Step 1: Begin authorization Send the user to this web page, with your values filled in: https://www.dropbox.com/oauth2/authorize?client_id=<app key>&response_type=code&redirect_uri=<...

Struct fields whose names begin with an uppercase letter are exported. All other names are unexported. type Account struct { UserID int // exported accessToken string // unexported } Unexported fields can only be accessed by code within the same package. As such, if you are ev...

An Xfermode (think "transfer" mode) works as a transfer step in drawing pipeline. When an Xfermode is applied to a Paint, the pixels drawn with the paint are combined with underlying pixels (already drawn) as per the mode: paint.setColor(Color.BLUE); paint.setXfermode(new PorterDuffXferm...

Warning: be sure you have at least 15 GB of free disk space. Compilation in Ubuntu >=13.04 Option A) Use Git Use git if you want to stay in sync with the latest Ubuntu kernel source. Detailed instructions can be found in the Kernel Git Guide. The git repository does not include necessary ...