#!/bin/python3
import sys
import random

def channelFrequencyGenerator(lower_frequency, upper_frequency):
    system_random = random.SystemRandom()
    return system_random.uniform(lower_frequency, upper_frequency)

def isfloat(num):
    try:
        float(num)
        return True
    except ValueError:
        return False
    
def isint(num):
    try:
        int(num)
        return True
    except ValueError:
        return False

def valid(argv):
    return (isfloat(argv[1]) and isfloat(argv[2]) and isfloat(argv[4]) and isint(argv[3]))

def verifyChannelSpacing(newchannel, channellist, spacing):
    for channel in channellist:
        if(newchannel - channel < spacing and channel - newchannel < spacing):
            return False
        else:
            return True

def createChannelList(argv):
    channellist= []
    channellist.append(round(channelFrequencyGenerator(float(argv[1]), float(argv[2])), 5))
    i = 1
    j = 0
    while i < int(argv[3]): 
            newchannel=round(channelFrequencyGenerator(float(argv[1]), float(argv[2])), 5)
            if(verifyChannelSpacing(newchannel, channellist, float(argv[4]))):
                    channellist.append(newchannel)
                    i+=1
            else:
                j+=1
                if j > 3 :
                    return channellist
    
    return channellist


if __name__ == '__main__':
    if (valid(sys.argv)):
        print(createChannelList(sys.argv))
    else: 
        print("invalid arguments")