{"id":523,"date":"2014-11-23T23:31:00","date_gmt":"2014-11-23T15:31:00","guid":{"rendered":"http:\/\/note.systw.net\/note\/?p=523"},"modified":"2023-11-03T23:33:37","modified_gmt":"2023-11-03T15:33:37","slug":"python-array","status":"publish","type":"post","link":"https:\/\/systw.net\/note\/archives\/523","title":{"rendered":"Python Array"},"content":{"rendered":"\n

python \u8655\u7406array\u4e3b\u8981\u6709\u4ee5\u4e0b\u4e09\u7a2e\u65b9\u5f0f
list ,dict , tuple<\/p>\n\n\n\n

…………………….
<\/p>\n\n\n\n

LIST<\/h2>\n\n\n\n

key\u53ea\u80fd\u70ba0,1,2,….\uff0c\u7b2c\u4e00\u500b\u5143\u7d20\u7684key\u70ba0<\/p>\n\n\n\n

\u5ba3\u544a<\/strong>
a=list()<\/p>\n\n\n\n

\u5ba3\u544a\u4e26\u76f4\u63a5\u7d66\u5143\u7d20<\/strong>
a = [2, ‘abc’, 10]<\/p>\n\n\n\n

\u986f\u793a<\/strong>
print a[2]
\u986f\u793a\u7b2c3\u500b\u5143\u7d20,\u7d50\u679c\u5982\u4e0b
10<\/p>\n\n\n\n

\u9078\u53d6\u4e00\u6bb5\u7bc4\u570d<\/strong>
print a[0:2]
\u53d6\u51fa a[0], a[1] \u800c\u4e0d\u5305\u542b a[2]
\u7d50\u679c\u5982\u4e0b
[2, \u2018abc’]<\/p>\n\n\n\n

\u9644\u52a0<\/strong>
a.append(\u2018good’)
print a
\u7d50\u679c\u5982\u4e0b
[2, ‘abc’, 10, \u2018good’]<\/p>\n\n\n\n

\u5143\u7d20\u6578\u91cf<\/strong>
print len(list)
\u7d50\u679c\u5982\u4e0b
4<\/p>\n\n\n\n

\u63d2\u5165<\/strong>
a.insert(2,’cool’)
print a
\u7d50\u679c\u5982\u4e0b
[2, ‘abc’,’cool’,10, \u2018good’]<\/p>\n\n\n\n

\u96c6\u5408\u904b\u7b97<\/strong>
list1=[0,1,2,3]
list2=[2,3,4,5]
print list(set(list1) & set(list2))\u3000#\u4ea4\u96c6, \u8f38\u51fa[2, 3]
print list(set(list1) | set(list2))\u3000#\u806f\u96c6, \u8f38\u51fa[0, 1, 2, 3, 4, 5]
print list(set(list1) ^ set(list2))\u3000#\u5dee\u96c6, \u8f38\u51fa[0, 1, 4, 5]<\/p>\n\n\n\n

\u53d6\u552f\u4e00<\/strong>
list1=[0,0,1,1,2,2,3,3]
print list(set(list1))
\u7d50\u679c\u5982\u4e0b
[0, 1, 2, 3]

….<\/p>\n\n\n\n

\u61c9\u7528<\/strong><\/p>\n\n\n\n

int\u8f49float<\/strong>
l1 = [1,2,3,4,5]
l2 = [float(i) for i in l1]
print l2
[1.0,2.0,3.0,4.0,5.0]<\/p>\n\n\n\n

\u986f\u793asparse matrix<\/strong><\/p>\n\n\n\n

\u986f\u793a\u4ee5\u4e0b5*6\u77e9\u9663\u8cc7\u6599
0 0 0 0 0 0
0 3 0 0 0 0
0 0 0 6 0 0
0 0 9 0 0 0
0 0 0 0 12 0<\/p>\n\n\n\n

def restore(sparse):\n\u3000row = sparse[0][0]\n\u3000column = sparse[0][1]\n\u3000array = [[0] * column for i in range(row)]\n\u3000k = 1\n\u3000for i in range(row):\n\u3000\u3000for j in range(column):\n\u3000\u3000\u3000if k <= sparse[0][2] and i == sparse[k][0] and j == sparse[k][1]:\n\u3000\u3000\u3000\u3000array[i][j] = sparse[k][2]\n\u3000\u3000\u3000\u3000k += 1\n\u3000\u3000\u3000else:\n\u3000\u3000\u3000\u3000array[i][j] = 0\n\u3000return array\n\nsparse = [\n[5, 6, 4],\n[1, 1, 3],\n[2, 3, 6],\n[3, 2, 9],\n[4, 4, 12]\n]\narray = restore(sparse)\nprint(array)<\/code><\/pre>\n\n\n\n
\u8aaa\u660e
\u4f7f\u7528\u7684\u9663\u5217\u7b2c\u4e00\u5217\u8a18\u9304:\u5217\u6578,\u884c\u6578,\u975e0\u5143\u7d20\u500b\u6578
\u56e0\u70ba\u9019\u500b\u77e9\u9663\u662f5X6\u77e9\u9663\uff0c\u4e14\u975e0\u5143\u7d20\u67094\u500b(3,6,9,12)
5 6 4
\u4f7f\u7528\u7684\u9663\u5217\u7b2c\u4e8c\u5217\uff0c\u8a18\u9304\u4f4d\u7f6e:\u5217\u7d22\u5f15,\u884c\u7d22\u5f15,\u5132\u5b58\u503c\uff1a
1 1 3
2 3 6
3 2 9
4 4 12<\/p>\n\n\n\n
refer
http:\/\/blog.eddie.com.tw\/2011\/10\/13\/python-list\/
…<\/p>\n\n\n\n
DICT<\/h2>\n\n\n\n
key\u53ef\u4ee5\u7528\u4efb\u4f55\u5b57\u4e32\u8868\u793a<\/p>\n\n\n\n
dictdata=dict()<\/strong>
\u5ba3\u544adictdata\u70badict\u7d50\u69cb
ex:
dictdata=dict()
dictdata[‘url1’]=1
dictdata[‘url2’]=2
print dictdata
\u7d50\u679c\u5982\u4e0b
{‘url1’: 1, ‘url2’: 2}<\/p>\n\n\n\n
dictdata.get(key)<\/strong>
\u5224\u65b7dictdata[key]\u662f\u5426\u5b58\u5728
ex:
if dictdata.get(‘url1’) != None
print \u2018url1 exist’
\u7d50\u679c\u5982\u4e0b
url1 exist<\/p>\n\n\n\n
dictdata.keys()<\/strong>
\u7d50\u679c\u5982\u4e0b
[‘url1’, ‘url2’]
ex:
\u5224\u65b7aaa\u7684key\u662f\u5426\u5728dictdata\u4e2d
if \u2018url1′ in dictdata.keys():
print \u2018url1 in dictdata’
\u7d50\u679c\u5982\u4e0b
url1 in dictdata<\/p>\n\n\n\n
dictdata.values()<\/strong>
\u7d50\u679c\u5982\u4e0b
[1, 2]<\/p>\n\n\n\n
dictdata.items()<\/strong>
\u7d50\u679c\u5982\u4e0b
[(‘url1’, 1), (‘url2’, 2)]
ex:
\u5217\u51fadict\u8cc7\u6599\u4e2d\u7684key\u548cvalue
for key,value in dictdata.items():
print key, value
\u7d50\u679c\u5982\u4e0b
url1 1
url2 2<\/p>\n\n\n\n
\u6392\u5e8f<\/strong>
dictdata.iteritems()
ex:
dictdata = {‘a’:6, ‘b’:5, ‘c’:3, ‘d’:4, ‘e’:7, ‘d’:0}
dicsorted= sorted(dictdata.iteritems(), key=lambda d:d[1], reverse = True)
print dicsorted
\u7d50\u679c\u70ba
[(\u2018e’,7),(\u2018a’,6),(\u2018b’,5),(\u2018d’,4),(\u2018d’,0)]
ps:
reverse = True \u8868\u793a\u7531\u591a\u5230\u5c0f\u6392\u5e8f
ex:
for key in sorted(mydict.iterkeys()):
print “%s: %s” % (key, mydict[key])<\/p>\n\n\n\n
LEN \u7b97\u9577\u5ea6<\/strong>
>>> mylist = [1,2,3] #list
>>> len(mylist)
3
>>> word = ‘hello’ # string
>>> len(word)
5
>>> vals = {‘a’:1,’b’:2} #dictionary
>>> len(vals)
2
>>> tup = (4,5,6) # tuple
>>> len(tup)
3<\/p>\n","protected":false},"excerpt":{"rendered":"
python \u8655\u7406array\u4e3b\u8981\u6709\u4ee5\u4e0b\u4e09\u7a2e\u65b9\u5f0flist ,d …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"","fifu_image_alt":"","_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[14],"tags":[],"class_list":["post-523","post","type-post","status-publish","format-standard","hentry","category-develop"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/523","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/comments?post=523"}],"version-history":[{"count":0,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/523\/revisions"}],"wp:attachment":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/media?parent=523"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/categories?post=523"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/tags?post=523"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}