[lorax] Fix rexists

[Martin Gracik]

---
 src/pylorax/ltmpl.py |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/pylorax/ltmpl.py b/src/pylorax/ltmpl.py
index 040f1aa..d716586 100644
--- a/src/pylorax/ltmpl.py
+++ b/src/pylorax/ltmpl.py
@@ -95,7 +95,11 @@ def rglob(pathname, root="/", fatal=False):
         raise IOError, "nothing matching %s in %s" % (pathname, root)

def rexists(pathname, root=""):
-    return True if rglob(pathname, root) else False
+    # Generator is always True, even with no values;
+    # bool(rglob(...)) won't work here.
+    for _path in rglob(pathname, root):
+        return True
+    return False

# TODO: operate inside an actual chroot for safety? Not that RPM bothers..
 class LoraxTemplateRunner(object):

[Vratislav Podzimek]

On Wed, 2012-12-19 at 12:40 +0100, Martin Gracik wrote:
> src/pylorax/ltmpl.py |    6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/src/pylorax/ltmpl.py b/src/pylorax/ltmpl.py
> index 040f1aa..d716586 100644
> --- a/src/pylorax/ltmpl.py
> +++ b/src/pylorax/ltmpl.py
> @@ -95,7 +95,11 @@ def rglob(pathname, root="/", fatal=False):
>          raise IOError, "nothing matching %s in %s" % (pathname, root)
>
> def rexists(pathname, root=""):
> return True if rglob(pathname, root) else False
> # Generator is always True, even with no values;
> # bool(rglob(...)) won't work here.
> for _path in rglob(pathname, root):
>    return True
> return False

I think

try:
    rglob(pathname, root).next()
    return True
except StopIteration:
    return False

would be better readable, but that's just a matter of opinion. ACK to
whichever from that two you prefer. :)

[Martin Gracik]

--

Martin Gracik

----- Original Message -----
> On Wed, 2012-12-19 at 12:40 +0100, Martin Gracik wrote:
> > src/pylorax/ltmpl.py |    6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/src/pylorax/ltmpl.py b/src/pylorax/ltmpl.py
> > index 040f1aa..d716586 100644
> > --- a/src/pylorax/ltmpl.py
> > +++ b/src/pylorax/ltmpl.py
> > @@ -95,7 +95,11 @@ def rglob(pathname, root="/", fatal=False):
> >          raise IOError, "nothing matching %s in %s" % (pathname,
> >          root)
> >
> > def rexists(pathname, root=""):
> > return True if rglob(pathname, root) else False
> > # Generator is always True, even with no values;
> > # bool(rglob(...)) won't work here.
> > for _path in rglob(pathname, root):
> >    return True
> > return False
>
> I think
>
> try:
>     rglob(pathname, root).next()
>     return True
> except StopIteration:
>     return False
>
> would be better readable, but that's just a matter of opinion. ACK to
> whichever from that two you prefer. :)

I really don't agree. :) What if sometime later rglob is changed to return a list instead of an iterator? Then your solution stops working and rexists needs to be changed too.
> --
> Vratislav Podzimek
>
> Anaconda Rider | Red Hat, Inc. | Brno - Czech Republic
>
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