Re: [PATCH v2] tools/kvm_stat: Add Python 3 support to kvm_stat

["Radim Krčmář" <rkrcmar@redhat.com>]

2017-10-04 03:08+0000, Jeremy Cline:
> Make kvm_stat support Python 3 by changing the use of "print" to a
> function rather than a statement, switching from "iteritems" and
> "iterkeys" (removed in Python 3) to "items" and "keys" respectively,
> and decoding bytes to strings when dealing with text.
> 
> With this change, kvm_stat is usable with Python 2.6 and greater.
> 
> Signed-off-by: Jeremy Cline <jeremy@jcline.org>
> ---
> There were a few flaws in my original patch that changed the behavior in
> Python 2. Additionally, I missed several compatibility problems with
> Python 3. Sorry!

No problem, you even sent a new version before I got to test it. :)

Queued for 4.15, thanks.

> Changes in v2:
>  - Include the "end=' '" argument in print statements that previously
>    had trailing commas since in Python 2 that causes the print
>    statement to not print a newline.
>  - decode bytes strings to text strings so that string concatenation
>    works properly in Python 3.
>  - replace "iterkeys" with "keys" as "iterkeys" is not in Python 3.
> 
>  tools/kvm/kvm_stat/kvm_stat | 30 +++++++++++++++++-------------
>  1 file changed, 17 insertions(+), 13 deletions(-)
> 
> diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
> index 32283d88701a..217cf6f95c36 100755
> --- a/tools/kvm/kvm_stat/kvm_stat
> +++ b/tools/kvm/kvm_stat/kvm_stat
> @@ -19,9 +19,11 @@ Three different ways of output formatting are available:
>  
>  The data is sampled from the KVM's debugfs entries and its perf events.
>  """
> +from __future__ import print_function
>  
>  import curses
>  import sys
> +import locale
>  import os
>  import time
>  import optparse
> @@ -225,6 +227,8 @@ IOCTL_NUMBERS = {
>      'RESET':       0x00002403,
>  }
>  
> +ENCODING = locale.getpreferredencoding(False)
> +
>  
>  class Arch(object):
>      """Encapsulates global architecture specific data.
> @@ -666,7 +670,7 @@ class TracepointProvider(Provider):
>          """Returns 'event name: current value' for all enabled events."""
>          ret = defaultdict(int)
>          for group in self.group_leaders:
> -            for name, val in group.read().iteritems():
> +            for name, val in group.read().items():
>                  if name in self._fields:
>                      ret[name] += val
>          return ret
> @@ -955,7 +959,7 @@ class Tui(object):
>          except:
>              raise Exception
>          for line in child.stdout:
> -            line = line.lstrip().split(' ', 1)
> +            line = line.decode(ENCODING).lstrip().split(' ', 1)
>              # perform a sanity check before calling the more expensive
>              # function to possibly extract the guest name
>              if ' -name ' in line[1]:
> @@ -1005,7 +1009,7 @@ class Tui(object):
>          name = ''
>          try:
>              line = open('/proc/{}/cmdline'
> -                        .format(pid), 'rb').read().split('\0')
> +                        .format(pid), 'r').read().split('\0')
>              parms = line[line.index('-name') + 1].split(',')
>              while '' in parms:
>                  # commas are escaped (i.e. ',,'), hence e.g. 'foo,bar' results
> @@ -1170,7 +1174,7 @@ class Tui(object):
>                                 .format(self.stats.fields_filter))
>              self.screen.addstr(3, 0, "New regex: ")
>              curses.echo()
> -            regex = self.screen.getstr()
> +            regex = self.screen.getstr().decode(ENCODING)
>              curses.noecho()
>              if len(regex) == 0:
>                  self.stats.fields_filter = DEFAULT_REGEX
> @@ -1204,7 +1208,7 @@ class Tui(object):
>  
>              curses.echo()
>              self.screen.addstr(3, 0, "Pid [0 or pid]: ")
> -            pid = self.screen.getstr()
> +            pid = self.screen.getstr().decode(ENCODING)
>              curses.noecho()
>  
>              try:
> @@ -1233,7 +1237,7 @@ class Tui(object):
>              self.screen.addstr(2, 0, 'Change delay from %.1fs to ' %
>                                 self._delay_regular)
>              curses.echo()
> -            val = self.screen.getstr()
> +            val = self.screen.getstr().decode(ENCODING)
>              curses.noecho()
>  
>              try:
> @@ -1273,7 +1277,7 @@ class Tui(object):
>              self.print_all_gnames(7)
>              curses.echo()
>              self.screen.addstr(3, 0, "Guest [ENTER or guest]: ")
> -            gname = self.screen.getstr()
> +            gname = self.screen.getstr().decode(ENCODING)
>              curses.noecho()
>  
>              if not gname:
> @@ -1369,25 +1373,25 @@ def batch(stats):
>          s = stats.get()
>          for key in sorted(s.keys()):
>              values = s[key]
> -            print '%-42s%10d%10d' % (key, values[0], values[1])
> +            print('%-42s%10d%10d' % (key, values[0], values[1]))
>      except KeyboardInterrupt:
>          pass
>  
>  
>  def log(stats):
>      """Prints statistics as reiterating key block, multiple value blocks."""
> -    keys = sorted(stats.get().iterkeys())
> +    keys = sorted(stats.get().keys())
>  
>      def banner():
>          for k in keys:
> -            print '%s' % k,
> -        print
> +            print(k, end=' ')
> +        print()
>  
>      def statline():
>          s = stats.get()
>          for k in keys:
> -            print ' %9d' % s[k][1],
> -        print
> +            print(' %9d' % s[k][1], end=' ')
> +        print()
>      line = 0
>      banner_repeat = 20
>      while True:
> -- 
> 2.13.6
>