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

From: Radim KrÄmÃÅ
Date: Thu Oct 05 2017 - 14:05:36 EST


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@xxxxxxxxxx>
> ---
> 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
>