lib_num.py

def conversion(input_num, con_from, con_to): 

    if con_from == "cm" and con_to == "m":
        ans = float(input_num)/100
        print(ans)
    elif con_from == "m" and con_to == "cm":
        ans = float(input_num)*100
        print(ans)
    elif con_from == "mm" and con_to == "cm":
        ans = float(input_num)/10
        print(ans)
    elif con_from == "cm" and con_to == "mm":
        ans = float(input_num)*10
        print(ans)
    elif con_from == "mm" and con_to == "m":
        ans = float(input_num)/1000
        print(ans)
    elif con_from == "m" and con_to == "mm":
        ans = float(input_num)*1000
        print(ans)
    elif con_from == "ft" and con_to == "cm":
        ans = float(input_num)*30.48
        print(ans)
    elif con_from == "ft" and con_to == "inch":
        ans = float(input_num)*12
        print(ans)
    elif con_from == "inch" and con_to == "cm":
        ans = float(input_num)*2.54
        print(ans)
    elif con_from == "inch" and con_to == "mm":
        ans = float(input_num)*25.4
        print(ans)
    else:
        print("There is no formula for the value entered. Please enter a new value..")