python函數定義與執行個體

python函數定義下面幾個執行個體是從最簡單函數傳回值到最函數裡面更複雜的運算式，但不管怎麼變是離不開函數這個東東。

def square(x):
    'Calculates the square of the number x.'
    return x*x

print square(100)

執行個體二

def power(x, n):
    if n == 0:
        return 1
    else:
        return x * power(x, n-1)

print power(2,7)

函數執行個體三

def hello():
    print "Hello, world!"

def test():
    hello()

if __name__ == '__main__': test()

執行個體四

def fib(n):    # write Fibonacci series up to n
     """Print a Fibonacci series up to n."""
     a, b = 0, 1
     while b < n:
         print b,
         a, b = b, a+b
 
# Now call the function we just defined:
fib(2000)

系統函數調用

def fib(n):    # write Fibonacci series up to n
     """Print a Fibonacci series up to n."""
     a, b = 0, 1
     while b < n:
         print b,
         a, b = b, a+b
 
# Now call the function we just defined:
fib(2000)