Bottom Page

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
 Grabbing a value from one python script into another
#1
Hi,
Very new to Python and trying to figure out how I can get the value from a variable in one script into another.

I have a python script called "Accelerator" which gets a constantly changing value from a UDP packet and then prints that value to the screen

-> print("Revs = " + str(int(revsPC)))

What I want to do is grab that value in revsPC pass it to another script and display it

I have tried the import i.e import Accelerator but this I understand executes the whole Accelerator script which throws up an error. I have also tried import revsPC from Accelerator but that doesn't seem to do anything.

Am I missing something really obvious? I am very new to python so my ignorance is high!

Thanks in advance for any help.
Quote
#2
# Accelerator.py
revs_pc = 999
if __name__ == '__main__':
    print(f"Revs = {revs_pc}")
# bar.py
import Accelerator
import math

def foo(arg):
    value = math.factorial(arg) + Accelerator.revs_pc
    return value

if __name__ == '__main__':
    print(foo(10))
Output:
3629799
So it's a good practice to use if __name__ == '__main__',then dos code after that do not execute when import it.
Have to call Accelerator.revs_pc to get 999.
Also look that i use f-string to avoid the not so nice way print("Revs = " + str(int(revsPC))).
Quote
#3
That's great and works a treat but the revsPC data is generated from a value inside a UDP packet where the connection is established at the start of the script and the the revsPC variable is inside a loop. I know my syntax is not great or neat but it does do the basic job of determining my revsPC value.
import sys
import socket
import time

UDP_IP = ""
UDP_PORT1 = 40002
sock1 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock1.bind((UDP_IP, UDP_PORT1))

#definition of the function for mapping a range values to another
def translate(value, inputMin, inputMax, outputMin, outputMax):
    
	# Figure out how 'wide' each range is
	inputSpan = inputMax - inputMin
	outputSpan = outputMax - outputMin

	# Convert the input range into a 0-1 range (float)
	valueScaled = float(value - inputMin) / float(inputSpan)

	# Convert the 0-1 range into a value in the output range.	
	return outputMin + (valueScaled * outputSpan)

counter = 0
while True:

	#Beginning of the program
	tmps1=time.time()

	data, addr = sock1.recvfrom(1024) # length of the buffer : 1024 bytes
	hiValRPM = data1[0]
	loValRPM = data1[1]

	print("--------------------------")
	print("Data Received : " + str(hiValRPM) + "/" + str(loValRPM))
	print(" ")

	#Revs : Mapping from 0-1023 to 0-6000
	if(hiValRPM == 0):
		revsPC = translate(loValRPM, 0, 255, 0, 1503)
	elif(hiValRPM == 1):
		revsPC = translate(loValRPM, 0, 255, 1504, 3004)
	elif(hiValRPM == 2):
		revsPC = translate(loValRPM, 0, 255, 3005, 4503)
	elif(hiValRPM == 3):
		revsPC = translate(loValRPM, 0, 255, 4504, 6000)

	print("Revs = " + str(int(revsPC)))

	#Calculation of the program execution time
	tmps2=(time.time()-tmps1)*1000
	print ("Execution time = %f ms" %tmps2)

	counter += 1
	
	print("Packet number : " + str(counter))
Yoriz wrote May-24-2019, 04:27 PM:
Please post all code, output and errors (in it's entirety) between their respective tags. I did it for you this time, Here are instructions on how to do it yourself next time.
Quote
#4
Now you run a infinity loop(while True) with no break out of the loop.
So need a way to get value out,one way can by to rewire it so it's a generator.
# Accelerator.py
import random
import time

def foo():
    while True:
        time.sleep(3)
        revs_pc = random.randint(1,10)
        yield revs_pc
# bar.py
import Accelerator

for i in range(10):
    revs_pc = next(Accelerator.foo())
    revs_pc += 9  # do something with revs_pc value
    print(revs_pc)
Output:
12 16 13 11 10 10 15 10 19 14
Quote

Top Page

Possibly Related Threads...
Thread Author Replies Views Last Post
  Grabbing a Subset of a String acemurdoc 3 354 Jun-18-2019, 04:57 PM
Last Post: perfringo
  Package python script which has different libraries as a single executable or script tej7gandhi 1 413 May-11-2019, 08:12 PM
Last Post: keames
  Grabbing questions from a quiz app CodingUnicorn 0 364 Mar-05-2019, 11:26 PM
Last Post: CodingUnicorn
  Check Python version from inside script? Run Pythons script in v2 compatibility mode? pstein 2 5,950 Jul-07-2017, 08:59 AM
Last Post: snippsat
  Cant pass corect variables to python script in bash script neradp 3 2,702 Nov-05-2016, 01:26 AM
Last Post: Larz60+

Forum Jump:


Users browsing this thread: 1 Guest(s)