Search results
Results from the WOW.Com Content Network
In all versions of Python, boolean operators treat zero values or empty values such as "", 0, None, 0.0, [], and {} as false, while in general treating non-empty, non-zero values as true. The boolean values True and False were added to the language in Python 2.2.1 as constants (subclassed from 1 and 0 ) and were changed to be full blown ...
The empty set is the set containing no elements. In mathematics, the empty set or void set is the unique set having no elements; its size or cardinality (count of elements in a set) is zero. [1] Some axiomatic set theories ensure that the empty set exists by including an axiom of empty set, while in
The number 0 is represented by zero while null is a representation of an empty set {}. Hence in computer science a zero represents the outcome of a mathematical computation such as 2−2, while null is used for an undefined state (for example, a memory location that has not been explicitly initialised).
Python 2.0 was released in 2000. Python 3.0, released in 2008, was a major revision not completely backward-compatible with earlier versions. Python 2.7.18, released in 2020, was the last release of Python 2. [37] Python consistently ranks as one of the most popular programming languages, and has gained widespread use in the machine learning ...
With zero-based numbering, a range can be expressed as the half-open interval, [0, n), as opposed to the closed interval, [1, n]. Empty ranges, which often occur in algorithms, are tricky to express with a closed interval without resorting to obtuse conventions like [1, 0].
In some programming language environments (at least one proprietary Lisp implementation, for example), [citation needed] the value used as the null pointer (called nil in Lisp) may actually be a pointer to a block of internal data useful to the implementation (but not explicitly reachable from user programs), thus allowing the same register to be used as a useful constant and a quick way of ...
between 2008 and 2012, better performance than 68% of all directors The Donald R. Keough Stock Index From January 2008 to December 2012, if you bought shares in companies when Donald R. Keough joined the board, and sold them when he left, you would have a 9.0 percent return on your investment, compared to a -2.8 percent return from the S&P 500.
The notion of null set should not be confused with the empty set as defined in set theory. Although the empty set has Lebesgue measure zero, there are also non-empty sets which are null. For example, any non-empty countable set of real numbers has Lebesgue measure zero and therefore is null.