When I was running a python file, an error occurred."TypeError: must be real number, not str&qu-CodePudding

p1.py

import sys


def sum(x1, x2):
    return (x1   x2)


x0 = sys.argv[1]
x1 = sys.argv[2]
x2 = sys.argv[3]
print("user is:"   x0)
print(x1)
print(x2)
print(sum(float(x1), float(x2)))
print("hello world")

p2.py

import os
import sys

paraA = sys.argv[0]
paraB = sys.argv[1]
paraC = sys.argv[2]
if __name__ == '__main__':
    os.system("python p1.py %s %f %f" % (paraA, paraB, paraC))

I run the code with:

python p2.py 3 6

and the error occur:

TypeError: must be real number, not str

Why is that? I want to transmit the name of p2 to p1.name is str not number. Why does the error occur?

CodePudding user response：

Error lies in this line;

os.system("python p1.py %s %f %f" % (paraA, paraB, paraC))

You are not converting the last two into float;

os.system("python p1.py %s %f %f" % (paraA, float(paraB), float(paraC)))

CodePudding user response：

sys.argv always give you "string", so this line will cause error when you cast a "string"(paraB,paraC) to "%f", which expect a "float".

os.system("python p1.py %s %f %f" % (paraA, paraB, paraC))

And in your case, instead of using "float(paraB)" in "p2.py", I suggest keeping them as string and make them float in p1.py, which your code already did that. This way you cause less trouble as float(1) will print "1.000000" with 6 zero as default.

p2.py

os.system("python p1.py %s %s %s" % (paraA, paraB, paraC))

p1.py

...
x1 = sys.argv[2]
x2 = sys.argv[3]
print(sum(float(x1), float(x2)))
...

CodePudding user response：

sys.argv values are considered as string.

Do this :

paraB = float(sys.argv[1])
paraC = float(sys.argv[2])

Hope it will help you