python - 整数乘以分数和小数时Python程序出错

Question

我试图编写一个简短的程序来计算著名的德雷克方程。我让它接受整数输入、小数输入和小数输入。但是，当程序尝试将它们相乘时出现此错误(在我输入所有必要的值后立即发生错误):

Traceback (most recent call last)
  File "C:/Users/Family/Desktop/Programming/Python Files/1/DrakeEquation1.py", line 24, in <module>
    calc() #cal calc to execute it
  File "C:/Users/Family/Desktop/Programming/Python Files/1/DrakeEquation1.py", line 17, in calc
    calc = r*fp*ne*fl*fi*fc*l
TypeError: can't multiply sequence by non-int of type 'str'

我的代码如下:

def intro():
    print('This program will evaluate the Drake equation with your values')

def calc():
    print('What is the average rate of star formation in the galaxy?')
    r = input()
    print('What fraction the stars have planets?')
    fp = input()
    ne = int(input('What is the average number of life supporting planets (per     star)?'))
    print('What fraction of these panets actually develop life')
    fl = input()
    print('What fraction of them will develop intelligent life')
    fi = input()
    print('What fraction of these civilizations have developed detectable technology?')
    fc = input()
    l = int(input('How long will these civilizations release detectable signals?'))
    calc = r*fp*ne*fl*fi*fc*l

    print('My estimate of the number of detectable civilizations is ' + calc + ' .')


if __name__=="__main__":
    intro() #cal intro to execute it 
    calc() #cal calc to execute it 

我需要更改什么才能解决此问题？

Answer 1

您需要将输入值转换为 float 。

r = float(input())

(注意:在低于 3 的 Python 版本中，使用 raw_input 而不是 input。)

其他变量依此类推。否则，您将尝试用一个字符串乘以一个字符串。

编辑:正如其他人指出的那样，calc 也不能使用 + 运算符连接到周围的字符串。为此使用字符串替换:

print('My estimate of the number of detectable civilizations is %s.' % calc)