[python]dict sort by key or value
熊熊忘記該怎麼 sort by value，查了一下網路記下來。
for key in sorted(mydict.iterkeys()): print "%s: %s" % (key, mydict[key])
for key, value in sorted(mydict.iteritems(), key=lambda (k,v): (v,k)): print "%s: %s" % (key, value)
# (IMHO) the simplest approach: def sortedDictValues1(adict): items = adict.items() items.sort() return [value for key, value in items] # an alternative implementation, which # happens to run a bit faster for large # dictionaries on my machine: def sortedDictValues2(adict): keys = adict.keys() keys.sort() return [dict[key] for key in keys] # a further slight speed-up on my box # is to map a bound-method: def sortedDictValues3(adict): keys = adict.keys() keys.sort() return map(adict.get, keys)
d= [ {'id':0, 'value':9}, {'id':1, 'value':100}, {'id':5, 'value':99}, {'id':3, 'value':19}, {'id':2, 'value':59} ] d.sort(key=lambda x:x['id']) #針對key 'id' 做sort d.sort(key=lambda x:x['value']) #針對key 'value' 做sort #以下用cmp，可以達到上面指定key的效果 d.sort(cmp=lambda x,y: cmp(x['id'], y['id'])) d.sort(cmp=lambda x,y: cmp(x['value'], y['value']))
class data: def __init__(self, _id, _value): self.id = _id self.value = _value c = [ data(0,9), data(1,100), data(5,99), data(3,19), data(2,59) ] c.sort(key=lambda x:x.id)#針對class member id 做sort c.sort(key=lambda x:x.value)#針對class member value 做sort #以下用cmp，可以達到上面指定key的效果 c.sort(cmp=lambda x,y: cmp(x.id, y.id) ) c.sort(cmp=lambda x,y: cmp(x.value, y.value))
