整个字符串命令和popen中的字符串列表之间的区别
我发现大多数程序员建议使用字符串列表来表示popen中的命令.但是，在我自己的项目中，我发现在更多情况下，整个字符串都可以工作.
I found most of the programmers suggest use list of strings to represent the command in popen. However, in my own project, I found a whole string works in more cases.
例如，以下作品
subprocess.Popen('pgrep -f "\./run"', stdout=subprocess.PIPE, shell=True).wait()
同时
subprocess.Popen(['pgrep', '-f', '"\./run"'], stdout=subprocess.PIPE, shell=True).wait()
没有.
我可以知道这两种实施方式之间的区别是什么，为什么第二种无法按预期工作?
May I know what's the difference between these two ways of implementation and why the second one does not work as expected?
第二个不应具有shell=True参数.相反，它应该是:
subprocess.Popen(['pgrep', '-f', '"\./run"'], stdout=subprocess.PIPE).wait().
The second should not have a shell=True parameter. Instead, it should be:
subprocess.Popen(['pgrep', '-f', '"\./run"'], stdout=subprocess.PIPE).wait().
shell参数设置是否在单独的shell中执行命令.也就是说，如果仅是为了执行命令而产生了一个新的外壳程序，则该外壳程序必须先解释该外壳程序，然后才能运行该命令.
The shell parameter sets whether or not to execute the command in a separate shell. That is, if a new shell should be spawned just to execute the command, which must be interpreted by the shell before it can be run.
但是，在提供字符串列表时，这不会产生第二个shell，因此(最少)更快.最好使用它来处理变量输入，因为它避免了字符串插值.
When providing a list of strings, however, this does not spawn a second shell, and thus is (minimally) faster. It is also better to use for processing variable input, because it avoids string interpolation.