Python modules and timing
Python libraries are arranged as modules, containing a number of functions and/or classes. These modules must be
imported before being used. You can either import the complete module, or you can import individual functions or classes to be used.
As an example, let's study the
time module. In MicrroPython the module is called utime (for micro-time) and it contains functions allowing us to delay execution for a certain amaount of time.
- sleep(t) sets the program to sleep for t seconds
- sleep_ms(t) sets the program to sleep for t ms
If, in our program which prints "Hello World!" we want to have the text printed only every second we could program this as follows:
import utime # import time would work as well
for i in range(5):
print("Hello World")
utime.sleep(1) # delay execution be 1 s, utime.sleep_ms(1000) would do the same. sleep_ms is not available in CPython
The other option is to import just the function to be used:
from utime import sleep_ms
for i in range(5):
print("Hello World!")
sleep_ms(1000) # note that utime in front of the sleep call has been omitted
In i similar way, you may use the functions of the math library:
In order to calculate sin(30 degrees) you need access to the
sin function. The
sin function however takes its parameter in radians such that you need the function
radians, converting values from degrees to radians, in addition.
This is how you would go about:
from math import sin,radians
print(sin(radians(30)))
Let's try these.
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Uli Raich - 2022-10-15
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