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.


-- Uli Raich - 2022-10-15

Comments

Edit | Attach | Watch | Print version | History: r4 < r3 < r2 < r1 | Backlinks | Raw View | Raw edit | More topic actions...
Topic revision: r2 - 2022-10-15 - UliRaich
 
  • Edit
  • Attach
This site is powered by the TWiki collaboration platform Powered by PerlCopyright © 2008-2024 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback