Can somebody explain the reasoning behind the following tests ??
>>> 1 and True
True
>>> {'foo': 'Foo'} and True
True
>>> {} and True
{}
>>>
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Related question: stackoverflow.com/questions/3826473/…tzot– tzot2010-12-05 20:12:58 +00:00Commented Dec 5, 2010 at 20:12
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2 Answers
Python doesn't have a boolean and or boolean or. Its and and or operators are coalescing, which means that they return the first non-true or true operand, or the second operand.
answered Nov 9, 2010 at 7:54
Ignacio Vazquez-Abrams
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In the context of Boolean operations, and also when expressions are used by control flow statements, the following values are interpreted as false: False, None, numeric zero of all types, and empty strings and containers (including strings, tuples, lists, dictionaries, sets and frozensets). All other values are interpreted as true.
The expression x and y first evaluates x; if x is false, its value is returned; otherwise, y is evaluated and the resulting value is returned.
The expression x or y first evaluates x; if x is true, its value is returned; otherwise, y is evaluated and the resulting value is returned.
For further reference read more on Boolean operations: http://docs.python.org/reference/expressions.html#boolean-operations
