Popen.communicate() returns (None, None) 即使脚本打印结果

Question

我对 Popen.communicate() 有疑问。

我有 return 字符串的脚本。

然后我编写了第二个脚本，它采用该变量。

v = "./myscript arg1 arg2"
com = subprocess.Popen(v, shell=True).communicate()
print com

com returns (None, None)。关键是我可以先在脚本中打印结果， shell 也打印结果。我不能只将该打印分配给变量。

当然是第一个脚本return的值，不是打印出来的。

Answer 1

来自docs：

Note that if you want to send data to the process’s stdin, you need to create the Popen object with stdin=PIPE. Similarly, to get anything other than None in the result tuple, you need to give stdout=PIPE and/or stderr=PIPE too.

因此，创建 Popen 对象：

subprocess.Popen("./myscript arg1 arg2", shell=True,
                 stdout=subprocess.PIPE, stderr=subprocess.PIPE)

Popen.communicate() returns (None, None) 即使脚本打印结果

Popen.communicate() returns (None, None) even if script print results

python

shell