# Convert C to F or F to C and return with result
 
select = True
while select:
    x = int(raw_input ('To convert Celsius to Farenheit, enter 1\nTo convert Farenheit to Celsius, enter 2\n'))   
    if x == 1 or x == 2:
        select = False
    else:
        print 'Only options are 1 or 2'            
 
#Convert C to F
if x == 1:
    def Tc_to_Tf ():        
        Tc = input ("What is the Celsius Temperature ?   " )
        Tf = 9.0/5.0 * Tc + 32
        return Tf
    Tf = Tc_to_Tf ()
    #.2f instructs Python that placeholder holds float number with 2decimal places. 
    print 'The temperature is %.2f Degrees Fahrenheit' %(Tf, )
 
#Convert F to C
if x == 2:
    def Tf_to_Tc ():
        Tf = input ("What is the Fahrenheit Temperature ?   " )
        Tc = (5.0/9.0)*(Tf - 32)
        return Tc
    Tc = Tf_to_Tc ()
    print 'The temperature is %.2f Degrees Celsius' %(Tc, )

if x in [1,2]:

if x==1 or 2:

if 0:
    print "0 is True"
else:
    print "0 is False"
 
if -1:
    print "-1 is True"
else:
    print "-1 is False"

sentinel=True  # a boolean variable...we'll use this in a bit!
value = 24 #and a number
 
# OK, we want to check that value is greater than -1
# and less than or equal to 23...
if value>-1 and 23:# oops, the right hand part of this always evaluates to true 
    print "1. True" # this gets printed...Doh!
else:
    print "1. False" # when we want this!
 
if -1 and value<=23: # Oops, now the left hand part always evaluates to True
    print "2. True"
else:
    print "2. False" # returns false, but it's still wrong! ^^
 
# What we meant was..
if value>-1 and value<=23: #phew now we're ok. Both sides are valid boolean expresions
    print "3. True..."
else:
    print "3. False..." # should return false!
 
# Something slightly different:
# Here we're using the value of a variable on one side, but it's safe
# to do so because it's a boolean variable!
# if sentinel is true and value is greater than 23 return true...
if sentinel and value>23: # both sides of the 'or' are boolean
    print "4. True...." # Yaay!
else:
    print "4. False..."

#Convert C to F
if x == 1:
    Tc = input ("What is the Celsius Temperature ?   " )
    print 'The temperature is %.2f Degrees Fahrenheit' % \
             (9.0/5.0 * Tc + 32 )

def Tc_to_Tf ():        
    Tc = input ("What is the Celsius Temperature ?   " )
    print 'The temperature is %.2f Degrees Fahrenheit' %(9.0/5.0 * Tc + 32 )
 
def Tf_to_Tc ():
    Tf = input ("What is the Fahrenheit Temperature ?   " )
    print 'The temperature is %.2f Degrees Celsius' %((5.0/9.0)*(Tf - 32) )
 
##--------------------------------------------------------------------------------------------------
## "select" is a python function and should not be used as a variable
selection = True
while selection:
    x = int(raw_input ('To convert Celsius to Farenheit, enter 1\nTo convert Farenheit to Celsius, enter 2\n'))   
    if x == 1:
        Tc_to_Tf ()
        selection = False
    elif x == 2:
        Tf_to_Tc ()
        selection = False
    else:
        print 'Only options are 1 or 2'

##--------------------------------------------------------------------------------------------------
## "select" is a python function and should not be used as a variable
selection = True
while selection:
    try:
        x = int(raw_input ('To convert Celsius to Farenheit, enter 1\nTo convert Farenheit to Celsius, enter 2\n'))   
        if x == 1:
            Tc_to_Tf ()
            selection = False
        elif x == 2:
            Tf_to_Tc ()
            selection = False
        else:
            print 'Only options are 1 or 2'
 
    except:
        print 'No letter please'

def f2c(t):
    """given t Fahrenheit return Celsius"""
    return 5/9.0 * (t - 32)
 
def c2f(t):
    """given t Celsius return Fahrenheit"""
    return 9/5.0 * t + 32