无法将字符串添加到Python中的字符串类型变量

Question

我想用python做一个非常简单的网络扫描器，我写了这个：

import subprocess
ip_range = input("Enter ip range:")
start_ip = input("Enter start ip:")
end_ip = input("Enter end ip:")
result = "Result:"
for ping in range(int(start_ip), int(end_ip)):
    ip = ip_range + str(ping)
    connect = subprocess.call(["ping", "-c1",ip])
    if connect == 0:
        result += "---"
        result += "Ping to ",ip,"was OK"
        result += "---"
    else:
        result + "Couldn't ping to " + str(ip)
        result + "---"
        pass
print(result)

除了一件事之外，所有这些都能正常工作。在这一部分

result + "Couldn't ping to " + str(ip)
result + "---"

结果不等于这段代码，我的意思是它只是写出结果。

Answer 1

result + "Couldn't ping to " + str(ip)是一个表达式，而不是一个语句。您不会将该值赋给result。尝试将+更改为+=。它将在result中存储值result + "Couldn't ping to " + str(ip)。