Tutorial by Topics: set

empty_set = set() # initialize an empty set literal_set = {'foo', 'bar', 'baz'} # construct a set with 3 strings inside it set_from_list = set(['foo', 'bar', 'baz']) # call the set function for a new set set_from_iter = set(x for x in range(30)) # use arbitrary iterables to create a set set_f...

SELECT column_1 [, column_2 ] FROM table_1 ORDER BY order_column LIMIT row_count [OFFSET row_offset] SELECT column_1 [, column_2 ] FROM table_1 ORDER BY order_column LIMIT [row_offset,] row_count "Limit" could mean "Max number of rows in a table". "Offset&q...

A Queryset is fundamentally a list of objects derived from a Model, by a compilation of database queries.

Regex101 defines \K functionality as: \K resets the starting point of the reported match. Any previously consumed characters are no longer included in the final match The \K escape sequence is supported by several engines, languages or tools, such as: boost (since ???) grep -P          ...

A set contains only one copy of each distinct element. Unlike some other programming languages, base R does not have a dedicated data type for sets. Instead, R treats a vector like a set by taking only its distinct elements. This applies to the set operators, setdiff, intersect, union, setequal an...

ParameterUsagenameName of your distribution.versionVersion string of your distribution.packagesList of Python packages (that is, directories containing modules) to include. This can be specified manually, but a call to setuptools.find_packages() is typically used instead.py_modulesList of top-level...

As database tables grow, it's often useful to limit the results of queries to a fixed number or percentage. This can be achieved using SQL Server's TOP keyword or OFFSET FETCH clause. ParameterDetailsTOPLimiting keyword. Use with a number.PERCENTPercentage keyword. Comes after TOP and limiting ...

A set is a collection of items which can be anything. Whatever operator we need to work on these sets are in short the set operators and the operation is also known as set operation. Basic set operation includes Union, Intersection as well as addition, subtraction, etc. Group-Object Gr...

To select rows with out duplicates change the WHERE clause to "RowCnt = 1" To select one row from each set use Rank() instead of Sum() and change the outer WHERE clause to select rows with Rank() = 1

Given an R object, we may require separate analysis for one or more parts of the data contained in it. The process of obtaining these parts of the data from a given object is called subsetting. Missing values: Missing values (NAs) used in subsetting with [ return NA since a NA index picks ...

The Set object lets you store unique values of any type, whether primitive values or object references. Set objects are collections of values. You can iterate through the elements of a set in insertion order. A value in the Set may only occur ONCE; it is unique in the Set's collection. Distinct val...