Re: [alsa-devel] [PATCH - hwmixvolume 4/9] hwmixvolume: use a with context to open files

14 Aug 2018

Hi,
On Aug 9 2018 00:56, Emmanuel Gil Peyrot wrote:
...
Signed-off-by: Emmanuel Gil Peyrot linkmauve@linkmauve.fr

diff --git a/hwmixvolume/hwmixvolume b/hwmixvolume/hwmixvolume
index 267228c..e82f32d 100755
--- a/hwmixvolume/hwmixvolume
+++ b/hwmixvolume/hwmixvolume
@@ -138,26 +138,20 @@ class Stream:
              subdevice = info.index
          filename = "/proc/asound/card%d/pcm%dp/sub%d/status" % (card, device, subdevice)
          try:

       f = open(filename, "r")




       with open(filename, "r") as f:


           for line in f.readlines():


               if line[:9] == "owner_pid":


                   return int(line.split(':')[1].strip())



I'm not oppose to use with (far from it I greatly prefer it.), however 
the with statement was firstly supported in Python 2.5:
https://docs.python.org/3.6/whatsnew/2.5.html#what-s-new-in-python-2-5
This mean that you drop python 2.4 or former, in this point I have no 
objections because it was already unsupported.
If you use Python 2.5 or later, you can use 'file()' instead of 
'open()'. Furthermore, FILE object returned by 'file()' (or 'open()') 
supports 'iterator' and you have no need to call '.readlines()' anymore,
thus:
```
...

       with file(filename, "r") as f:


           for line in f:



...
```
...
      except IOError:
          return None


   try:


       for line in f.readlines():


           if line[:9] == "owner_pid":


               return int(line.split(':')[1].strip())


   finally:


       f.close()
    return None

def get_pid_cmdline(self, pid):
    try:


       f = open("/proc/%d/cmdline" % pid, "r")




       with open("/proc/%d/cmdline" % pid, "r") as f:


           cmdline = f.read()
    except IOError:
        return None




   try:


       cmdline = f.read()


   finally:


       f.close()
    return cmdline.replace('\x00', ' ').strip()


class MixerWindow(Gtk.Window):


Regards
Takashi Sakamoto

    