默认情况下,echo命令返回换行符
与此比较:
print(subprocess.Popen("echo -n hi", shell=True, stdout=subprocess.PIPE).communicate()[0])至于字符串前面的 b ,则表明它是一个字节序列,等效于Python 2.6+中的常规字符串
http://docs.python.org/3/reference/lexical_analysis.html#literals

默认情况下,echo命令返回换行符
与此比较:
print(subprocess.Popen("echo -n hi", shell=True, stdout=subprocess.PIPE).communicate()[0])至于字符串前面的 b ,则表明它是一个字节序列,等效于Python 2.6+中的常规字符串
http://docs.python.org/3/reference/lexical_analysis.html#literals