subprocess.Popen返回空的串？

Question

想用下面两句获取 Android 手机屏幕分辨率，为什么 size 是空的？

process = subprocess.Popen("adb wm size", shell=True,stdout=subprocess.PIPE)
size = process.stdout.read()
print(size)

Answer 1

process = subprocess.Popen("adb wm size", shell=True,stdout=subprocess.PIPE)
size = process.communicate()