Python: TypeError: can only concatenate str (not "int") to str : variable stored wrong

Hi Need clarification for python variable stored as wrong value , here is code :

userinput1 = int(input('enter start value\n'))
userinput2 = int(input('enter stop value\n'))
userinput3 = int(input('enter rampup time in seconds\n'))
userinput4 = float(input('enter  increments delta \n'))
userinput5 = input('Enter sequence channels: A A A A or D D D D - A Ascend, D Descent , E Exclude \n')
command1 = "RAMP " + str(userinput5) + " " + userinput1 + " " + userinput2 + " " + userinput4 + " " + userinput3
port.write(command1.encode())


#### ERROR #####

command1 = str("RAMP " + str(userinput5) + " " + userinput1 + " " + userinput2 + " " + userinput4 + " " + userinput3)
TypeError: can only concatenate str (not "int") to str

Can you please clarify me correct method to store both type variable input in single variable command. type caste was done already.