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Gadfly is a collection of Python modules that provides relational database functionality entirely implemented in Python. It supports a subset of the standard RDBMS Structured Query Language (SQL). [1] [2] Gadfly runs wherever Python runs and supports client/server on any platform that supports the standard Python socket interface.
[4]: 114 A DataFrame is a 2-dimensional data structure of rows and columns, similar to a spreadsheet, and analogous to a Python dictionary mapping column names (keys) to Series (values), with each Series sharing an index. [4]: 115 DataFrames can be concatenated together or "merged" on columns or indices in a manner similar to joins in SQL.
In computer programming, array slicing is an operation that extracts a subset of elements from an array and packages them as another array, possibly in a different dimension from the original.
In computing, NaN (/ n æ n /), standing for Not a Number, is a particular value of a numeric data type (often a floating-point number) which is undefined as a number, such as the result of 0/0.
The BJData Python module, pybj, [4] enabling reading/writing BJData/UBJSON files, is also available on PyPI, Debian/Ubuntu and GitHub. For MATLAB and GNU Octave, JSONLab v2.0 is the reference implementation for the latest JData specification, and is available on Debian/Ubuntu, Fedora, and GitHub.
Cypher also contains keywords to specify clauses for writing, updating, and deleting data. CREATE and DELETE are used to create and delete nodes and relationships. SET and REMOVE are used to set values to properties and add/delete labels on nodes. MERGE is used to create nodes uniquely without duplicates.
In JavaScript, the empty string (""), null, undefined, NaN, +0, −0 and false [3] are sometimes called falsy (of which the complement is truthy) to distinguish between strictly type-checked and coerced Booleans (see also: JavaScript syntax#Type conversion). [4] As opposed to Python, empty containers (Arrays, Maps, Sets) are considered truthy.
E. F. Codd mentioned nulls as a method of representing missing data in the relational model in a 1975 paper in the FDT Bulletin of ACM-SIGMOD.Codd's paper that is most commonly cited with the semantics of Null (as adopted in SQL) is his 1979 paper in the ACM Transactions on Database Systems, in which he also introduced his Relational Model/Tasmania, although much of the other proposals from ...