python - 我可以从 print 语句调用 Python 中的函数吗？

Question

我是Python新手，正在探索。现在，在下面的代码中，我尝试从 print 语句调用函数，这合法吗？

# My func
def summer(num1,num2):
print "The summation of the numbers is: %d " % (num1+num2)

num1 = raw_input("Enter a number: ")
num2 = raw_input("Enter another number: ")

print "Again, the summation: %d " % (summer(num1,num2))

print "That is the end of the program."

现在就到了

 print "Again, the summation: %d " % (summer(num1,num2))

有效吗？我收到错误。
我可以用这种方式从字符串调用函数吗？谢谢。

我得到的错误是:

  Traceback (most recent call last):
  File "myfunc.py", line 9, in <module>
  summer(num1,num2)
  File "myfunc.py", line 3, in summer
  print "The summation of the numbers is: %d " % (num1+num2)
  TypeError: %d format: a number is required, not str

Answer 1

您需要缩进方法中的代码，并返回一个字符串。您还需要将字符串转换为整数:

def summer(num1,num2):
    return "The summation of the numbers is: %d " % (int(num1)+int(num2))

num1 = raw_input("Enter a number: ")
num2 = raw_input("Enter another number: ")

print "Again, the summation: %s " % (summer(num1,num2))

print "That is the end of the program."