Reversing a dict?

[krumblebunk]

Hi - further to my earlier query regarding partial matches (which with
all your replies enabled me to advance my understanding, thanks), I
now need to reverse a dict.

I know how to reverse a list (with the reverse method - very handy),
but it doesn't seem possible to reverse a dict.

I suspect what I need to do is somehow go from:

thelist=list(thedict)
thelist.reverse()
thedict=dict(thelist)

Does anyone know how to convert / or reverse a dict?

thanks

kb.

[cokofreedom]

On May 6, 5:20 pm, [e-mail] wrote:

Hi - further to my earlier query regarding partial matches (which with
all your replies enabled me to advance my understanding, thanks), I
now need to reverse a dict.

I know how to reverse a list (with the reverse method - very handy),
but it doesn't seem possible to reverse a dict.

I suspect what I need to do is somehow go from:

thelist=list(thedict)
thelist.reverse()
thedict=dict(thelist)

Does anyone know how to convert / or reverse a dict?

thanks

kb.

Issue 1: A dictionary is not ordered so cannot be reversed, as is.

Saw something like this though:

info = {"PHP":"17th May",
"Perl":"15th June",
"Java":"7th June",
"Python":"26th May",
"Tcl":"12th July",
"MySQL":"24th May"}

topics = info.keys()
topics.sort()
topics.reverse()

for topic in topics:
print "Next",topic,"course starts",info[topic]

[krumblebunk]

Thanks all!!

kb.

[Paul Hankin]

On May 6, 4:24*pm, [e-mail] wrote:

On May 6, 5:20 pm, [e-mail] wrote:

Hi - further to my earlier query regarding partial matches (which with
all your replies enabled me to advance my understanding, thanks), I
now need to reverse a dict.

I know how to reverse a list (with the reverse method - very handy),
but it doesn't seem possible to reverse a dict.

I suspect what I need to do is somehow go from:

thelist=list(thedict)
thelist.reverse()
thedict=dict(thelist)

Does anyone know how to convert / or reverse a dict?

thanks

kb.

Issue 1: A dictionary is not ordered so cannot be reversed, as is.

Saw something like this though:

info = {"PHP":"17th May",
* * * *"Perl":"15th June",
* * * *"Java":"7th June",
* * * *"Python":"26th May",
* * * *"Tcl":"12th July",
* * * *"MySQL":"24th May"}

topics = info.keys()
topics.sort()
topics.reverse()

for topic in topics:
* *print "Next",topic,"course starts",info[topic]

Better:

for topic, when in sorted(topics.iteritems(), reverse=True):
print 'Next %s course starts %s' % (topic, when)

--
Paul Hankin