temperature = input("What's the current temperature in your city? (please use the format ??C or ???F) >>> ")
### warning... the result from input will <str> on Python 3.x only
### in the case of Python 2.x, the result from input is the variable type <int>
### for the <str> type as the result for Python 2.x it's neccessary to use the another: raw_input()
temp_int = int(temperature[:-1]) # 25 <int> (as example)
temp_str = temperature[-1:] # "C" <str> (as example)
if temp_str.lower() == 'c':
print("Your temperature in Fahrenheit is: {}".format( (9/5 * temp_int) + 32 ) )
elif temp_str.lower() == 'f':
print("Your temperature in Celsius is: {}".format( ((5/9) * (temp_int - 32)) ) )