#!/usr/bin/env python

def printIntroduction():
	"""Print introduction."""
	print "This program converts Celsius to/from Fahrenheit temperature."
	print
	

def celsius2Fahrenheit():
	"""Convert a Celsius degree to a corresponding Fahrenheit degree."""
	celsius = input("What is the Celsius temperature? ")
	print "The temperature is", c2f(celsius), "degrees Fahrenheit."
	print

	
def fahrenheit2Celsius():
	"""Convert a Fahrenheit degree to a corresponding Celsius degree."""
	fahrenheit = input("What is the Fahrenheit temperature? ")
	print "The temperature is", f2c(fahrenheit), "degrees Celsius."
	print
	

def printTable_c2f():
	"""Print Celsius degreess to Fahrenheit degrees."""
	print "celsius\tfahrenheit"
	for celsius in range(0, 101, 20):
		print celsius, "\t", c2f(celsius)
	print


def printTable_f2c():
	"""Print Fahrenheit degrees to Celsius degrees."""
	print "fahrenheit\tcelsius"
	for fahrenheit in range(200, 99, -20):
		print fahrenheit, "\t", f2c(fahrenheit)
	print


def printTable():
	"""Print Fahrenheit degrees to Celsius degrees and Fahrenheit degrees again."""
	print "celsius\tfahrenheit\tcelsius"
	for celsius in range(0, 101, 20):
		print celsius, "\t", c2f(celsius), "\t", f2c(c2f(celsius))
	print


def c2f(celsius=0):
	"""Convert a Celsius degree to a corresponding Fahrenheit degree.
	Keyword argument:
	celsius -- the celsius degree to convert (default 0)
	
	"""
	return 9.0 / 5.0 * celsius + 32;


def f2c(fahrenheit=0):
	"""Convert a Fahrenheit degree to a corresponding Celsius degree.
	Keyword argument:
	fahrenheit -- the fahrenheit degree to convert (default 0)
	
	"""
	return (fahrenheit - 32) * 5.0 / 9.0


if __name__ == "__main__":
	printIntroduction()
	celsius2Fahrenheit()
	fahrenheit2Celsius()
	printTable_c2f()
	printTable_f2c()
	printTable()