38. timer — A timer class.¶
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class timer.Timer(start=None, tag=None)[source]¶
- A class for measuring elapsed time. - A Timer object measures elapsed real time since a specified time, which by default is the time of the creation of the Timer. A builtin tag can be used for identifying subsequent measurements. - Parameters: - start: a datetime object. If not specified, the time of the creation of the Timer is used.
- tag: a string used as an identifier for the current measurement. It is displayed when printing the Timer value
 - Example: - >>> import time >>> t = Timer() >>> time.sleep(1.234) >>> r = t.read() >>> print(r.days, r.seconds, r.microseconds) # doctest: +ELLIPSIS 0 1 23... >>> t.seconds() # doctest: +ELLIPSIS 1.23... >>> t.seconds(rounded=True) 1 - Note that the precise result of microseconds will be slightly larger than the input sleep time. The precise result is unknown, therefore ellipses are shown. - >>> tim = Timer(tag="First") >>> time.sleep(0.13) >>> print(tim) Timer: First: 0.13 sec. >>> tim.reset(tag="Next") >>> time.sleep(0.13) >>> print(tim) Timer: Next: 0.13 sec. - 
reset(start=None, tag=None)[source]¶
- (Re)Start the timer. - Sets the start time of the timer to the specified value, or to the current time if not specified. Sets the tag to the specified value or to ‘None’. - Parameters: - start: a datetime object. If not specified, the current time as returned by datetime.now() is used.
- tag: a string used as an identifier for the current measurement
 
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read(reset=False)[source]¶
- Read the timer. - Returns the elapsed time since the last reset (or the creation of the timer) as a datetime.timedelta object. - If reset=True, the timer is reset to the time of reading. 
 
 
  