Python 3 -Functions

# computes the area of a triangle

def triangle_area(base, height): # header - ends in colon，以冒号结尾

area = (1.0 / 2) * base * height # body - all of body is indented，body必须要退格

return area # body - return outputs value

a1 = triangle_area(3, 8)

print a1

a2 = triangle_area(14, 2)

print a2

# converts fahrenheit to celsius

def fahrenheit2celsius(fahrenheit):

celsius = (5.0 / 9) * (fahrenheit - 32)

return celsius

# test!!!

c1 = fahrenheit2celsius(32)

c2 = fahrenheit2celsius(212)

print c1, c2

# converts fahrenheit to kelvin

def fahrenheit2kelvin(fahrenheit):

celsius = fahrenheit2celsius(fahrenheit)

kelvin = celsius + 273.15

return kelvin

# test!!!

k1 = fahrenheit2kelvin(32)

k2 = fahrenheit2kelvin(212)

print k1, k2

# prints hello, world!

def hello():

print "Hello, world!"

# test!!!

hello() # call to hello prints "Hello, world!"

h = hello() # call to hello prints "Hello, world!" a second time

print h # prints None since there was no return value