跟着文档学python(二):time.time() 与 time.clock() 的对比与总结
一,两个函数的文档:
1,time.time():
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- time.time()
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Return the time in seconds since the epoch as a floating point number. Note that even though the time is always returned as a floating point number, not all systems provide time with a better precision than 1 second. While this function normally returns non-decreasing values, it can return a lower value than a previous call if the system clock has been set back between the two calls.
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- time.time()
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返回从纪元(1970.1.1)至今的秒数。虽然这个函数的返回值永远为浮点数,但并不是所有系统提供的秒数都会精确到小数点以后。一般情况下这个函数的返回值不会小于它上一次被调用的返回值,除非系统时钟在两次调用之间发生了重置。
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2,time.clock():
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- time.clock()
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On Unix, return the current processor time as a floating point number expressed in seconds. The precision, and in fact the very definition of the meaning of “processor time”, depends on that of the C function of the same name, but in any case, this is the function to use for benchmarking Python or timing algorithms.
On Windows, this function returns wall-clock seconds elapsed since the first call to this function, as a floating point number, based on the Win32 function QueryPerformanceCounter(). The resolution is typically better than one microsecond.
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- time.clock()
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在Unix 中,将当前的处理器时间以浮点数的形式返回,单位为秒。它的精确度(准确地说是“处理器时间”的精确度)取决于同名的C函数,无论如何,这个函数是python关于时间计算的标尺。
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WINDOWS中,第一次调用,返回的是进程运行的实际时间。而第二次之后的调用是自第一次调用以后到现在的运行时间。(实际上是以WIN32上QueryPerformanceCounter()为基础,它比毫秒表示更为精确)
- 二,用法及总结
- 1,在Windows中,time.clock()更精确;
- 2,这两个函数不可以混合使用;
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(未完待续)