2018-10-12 20:35:31 +00:00
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---
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title: Python Bool Function
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localeTitle: Python Bool函数
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---
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`bool()`是Python 3中的内置函数。此函数返回一个布尔值,即True或False。它需要一个参数, `x` 。
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## 参数
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2019-01-04 20:02:12 +00:00
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它需要一个参数`x` 。使用标准[真值测试程序](https://docs.python.org/3/library/stdtypes.html#truth)转换`x` 。
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2018-10-12 20:35:31 +00:00
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2019-01-04 20:02:12 +00:00
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## 返回值
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2018-10-12 20:35:31 +00:00
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如果`x`为false或省略,则返回`False` ;否则返回`True` 。
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## 代码示例
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```
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print(bool(4 > 2)) # Returns True as 4 is greater than 2
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2019-01-04 20:02:12 +00:00
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print(bool(4 < 2)) # Returns False as 4 is not less than 2
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print(bool(4 == 4)) # Returns True as 4 is equal to 4
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print(bool(4 != 4)) # Returns False as 4 is equal to 4 so inequality doesn't holds
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print(bool(4)) # Returns True as 4 is a non-zero value
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print(bool(-4)) # Returns True as -4 is a non-zero value
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print(bool(0)) # Returns False as it is a zero value
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print(bool('dskl')) # Returns True as the string is a non-zero value
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print(bool([1, 2, 3])) # Returns True as the list is a non-zero value
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print(bool((2,3,4))) # Returns True as tuple is a non-zero value
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print(bool([])) # Returns False as list is empty and equal to 0 according to truth value testing
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2018-10-12 20:35:31 +00:00
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```
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2019-01-04 20:02:12 +00:00
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[运行代码](https://repl.it/CVCS/2)
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2018-10-12 20:35:31 +00:00
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2019-01-04 20:02:12 +00:00
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[官方文件](https://docs.python.org/3/library/functions.html#bool)
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