51 lines
1.7 KiB
Markdown
51 lines
1.7 KiB
Markdown
---
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title: Python Boolean Operations
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---
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<a href='https://docs.python.org/3/reference/expressions.html#or' target='_blank' rel='nofollow'>`or`</a>, <a href='https://docs.python.org/3/reference/expressions.html#and' target='_blank' rel='nofollow'>`and`</a>, <a href='https://docs.python.org/3/reference/expressions.html#not' target='_blank' rel='nofollow'>`not`</a>
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<a href='https://docs.python.org/3/library/stdtypes.html#boolean-operations-and-or-not' target='_blank' rel='nofollow'>Python Docs - Boolean Operations</a>
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These are the Boolean operations, ordered by ascending priority:
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Operation | Result | Notes
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--------- | ------------------------------------ | -----
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x or y | if x is false, then y, else x | (1)
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x and y | if x is false, then x, else y | (2)
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not x | if x is false, then True, else False | (3)
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**Notes:**
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1. This is a short-circuit operator, so it only evaluates the second argument if the first one is False.
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2. This is a short-circuit operator, so it only evaluates the second argument if the first one is True.
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3. `not` has a lower priority than non-Boolean operators, so `not a == b` is interpreted as `not (a == b)`, and `a == not b` is a syntax error.
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## Examples:
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### `or`:
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>>> True or False # Short-circuited at first argument.
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True
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>>> False or True # Second argument is evaluated.
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True
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>>> False or False # Second argument is evaluated.
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False
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### `and`:
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>>> True and False # Second argument is evaluated.
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False
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>>> False and True # Short-circuted at first argument.
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False
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>>> True and True # Second argument is evaluated.
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True
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### `not`:
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>>> not True
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False
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>>> not False
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True
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>>> False or False # Second argument is evaluated.
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False
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