为什么python脚本运行但屏幕上什么都没有显示

Question

I am a beginner in python programming but the challenge I am facing now is that anytime I run a script containing functions nothing shows on screen.

Example is the code below:

def add(a,b):
         print "Adding %d + %d" %(a, b)
         return a +b

def subtract(a, b):
         print "Subtracting %d - %d"%(a, b)
         return a-b

def multiply(a, b):
         print "Multiplying %d * %d" %(a, b)
         return a * b

def divide(a, b):
         print "Dividing %d / %d" %(a, b)
         return a / b


         print "Lets do some math with just functions!"

         age = add(30,5)
         height = subtract(78, 4)
         weight = multiply(90, 2)
         iq = divide(100, 2)


         print "Age: %d, Height: %d, Weight: %d, IQ: %d"%(age,height,weight)

  # A puzzle for the extra credit, type it in anyway.
  print "Here is a puzzle."

         what = add(age, subtract(height, multiply(weight, divide(iq, 2))))

         print "That becomes: ", what, "Can you do it by hand?"[enter image description here][1]

Answer 1

Indentation is very important in Python (also sorry to see that the IQ is set to 50)

def add(a,b):
         print "Adding %d + %d" % (a, b)
         return a + b

def subtract(a, b):
         print "Subtracting %d - %d" % (a, b)
         return a - b

def multiply(a, b):
         print "Multiplying %d * %d" % (a, b)
         return a * b

def divide(a, b):
         print "Dividing %d / %d" % (a, b)
         return a / b

print "Lets do some math with just functions!"

age = add(30,5)
height = subtract(78, 4)
weight = multiply(90, 2)
iq = divide(100, 2)

print "Age: %d, Height: %d, Weight: %d, IQ: %d" % (age, height, weight, iq)

# A puzzle for the extra credit, type it in anyway.
print "Here is a puzzle."

what = add(age, subtract(height, multiply(weight, divide(iq, 2))))

print "That becomes: ", what, "Can you do it by hand?"

Answer 2

Your indentation is all messed up. In Python, indents are what tells the interpreter where the code should be in the sense that it says whether a piece of code should be inside a function or not for example. I also believe you have a strange problem with your editor. As this is a Learn Python the Hard Way you may want to setup your editor like the author says in the start of the book. Please comment if anything is missing and I'll update my answer!

def add(a, b):
    print "ADDING %d + %d" % (a, b)
    return a + b

def subtract(a, b):
    print "SUBTRACTING %d - %d" % (a, b)
    return a - b

def multiply(a, b):
    print "MULTIPLYING %d * %d" % (a, b)
    return a * b

def divide(a, b):
    print "DIVIDING %d / %d" % (a, b)
    return a / b


print "Let's do some math with just functions!"

age = add(30, 5)
height = subtract(78, 4)
weight = multiply(90, 2)
iq = divide(100, 2)

print "Age: %d, Height: %d, Weight: %d, IQ: %d" % (age, height, weight, iq)


# A puzzle for the extra credit, type it in anyway.
print "Here is a puzzle."

what = add(age, subtract(height, multiply(weight, divide(iq, 2))))

print "That becomes: ", what, "Can you do it by hand?"