Python: изменить время в зависимости от другой переменной?

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I am working on a financial budget and may not be familiar to some of you. 

I created this script to call parameters from a file parameter:

    Net=$10'000'000
    Extract from file (salary1 =19000, salary2= 15000, salary3 = 19000 sometimes change) 
    parametersAndValues = {}
    parameterFile = open('Parameter') 
    try:
    	for line in parameterFile:
    		parametersAndValues[line.split()[0]] = int(round(float(line.split()[1])))
    finally:
    	parameterFile.close()
    
    i1 = parametersAndValues.get('$salary1')
    i2 = parametersAndValues.get('$salary2')
    i3 = parametersAndValues.get('$salary3')
    for parameter in parametersAndValues:
    	( parameter + ' = ' + str(parametersAndValues.get(parameter)))
    time1=0.1*(net/salary1) 
    time2 in TSTEP of salary2=time1+time1*(salary1/(salary1+salary2))
    time3 of salary3 = time2+time1


I want to update the timesteps under `TSTEP` depending on the salary payment. 
To see how many months that salary can be paid.

If we divided Net 10'000'000/on salary1 19'000=526 Days = which will be 17 months of 31 Days (17*31)

The output should be `17*31` which will be pasted under `TSTEP` for the first salary and `27*31` which will be pasted under `TSTEP` for salary 2.

The question is, I need to change `3*31` in each TSTEP depending on the salary, and I have no idea of how to do that.

The following is a sample `Schedule` file to be updated from `parameter` file:


    SCHEDULE
    
    
    ##-- First Cycle
    /   
    WCLSIN
    Class1  LIQ  OPEN  RESV  1*  $salary1  1*  3500 /
    /
    /
    TSTEP 
      3*31
  
      /
       
    TUNING
     /
     /
     2*  100 /
    ##-- Second Cycle
    WCLSIN
    Class1  LIQ  OPEN  RESV  1*  $salary2  3500 /
    /
    TSTEP 
      3*31
    /
    TUNING
     /
     /
     2*  100 /

It should be changed to:


    SCHEDULE
    
    
    ##-- First Cycle
    /   
    WCLSIN
    Class1  LIQ  OPEN  RESV  1*  $salary1  1*  3500 /
    /
    /
    TSTEP 
      17*31
    
      /
    
    TUNING
     /
     /
     2*  100 /
    ##-- Second Cycle
    WCLSIN
    Class1  LIQ  OPEN  RESV  1*  $salary2  3500 /
    /
    TSTEP 
      27*31
    /
    TUNING
     /
     /
     2*  100 /

Again, please if you have any idea of how to do that I would really appreciate it. 
Best Regards

Что я уже пробовал:

with open('schedule.txt') as f:  # Mode 'r' is default, no need to specify.
    for current_line in f.read().split('\n'):
        if previous_line == 'TSTEP':
            new_lines.append(str(time1))
        else:
            new_lines.append(current_line)
        previous_line = current_line

new_text = '\n'.join(new_lines)
open('schedule.txt', 'w').write(new_text)

Проблема в том, что есть две ступени, представляющие разные зарплаты, и я не знаю, как сделать вторую зарплату ??

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