{"id":1091108,"date":"2025-01-08T14:08:31","date_gmt":"2025-01-08T06:08:31","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/1091108.html"},"modified":"2025-01-08T14:08:33","modified_gmt":"2025-01-08T06:08:33","slug":"python%e4%b8%ad%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8%e8%ae%a1%e6%95%b0%e5%99%a8-2","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/1091108.html","title":{"rendered":"Python\u4e2d\u5982\u4f55\u4f7f\u7528\u8ba1\u6570\u5668"},"content":{"rendered":"

\"Python\u4e2d\u5982\u4f55\u4f7f\u7528\u8ba1\u6570\u5668\"<\/p>\n

Python\u4e2d\u4f7f\u7528\u8ba1\u6570\u5668\u7684\u65b9\u6cd5\u5305\u62ec\u4f7f\u7528collections.Counter\u7c7b\u3001\u4f7f\u7528\u5b57\u5178\u3001\u4f7f\u7528defaultdict\u3001\u4f7f\u7528\u5217\u8868\u7b49\uff0c\u8fd9\u4e9b\u65b9\u6cd5\u90fd\u53ef\u4ee5\u5b9e\u73b0\u5143\u7d20\u8ba1\u6570\u7684\u529f\u80fd\u3002\u672c\u6587\u5c06\u4e3b\u8981\u8be6\u7ec6\u4ecb\u7ecd\u5982\u4f55\u4f7f\u7528collections.Counter\u7c7b\u6765\u5b9e\u73b0\u8ba1\u6570\u5668\u529f\u80fd\u3002<\/strong><\/p>\n<\/p>\n

collections.Counter\u662fPython\u6807\u51c6\u5e93collections\u6a21\u5757\u4e2d\u7684\u4e00\u4e2a\u7c7b\uff0c\u4e13\u95e8\u7528\u4e8e\u8ba1\u6570\u3002\u5b83\u7684\u4f7f\u7528\u975e\u5e38\u7b80\u5355\u4e14\u529f\u80fd\u5f3a\u5927\uff0c\u53ef\u4ee5\u65b9\u4fbf\u5730\u7edf\u8ba1\u53ef\u8fed\u4ee3\u5bf9\u8c61\u4e2d\u5143\u7d20\u7684\u9891\u7387\u3002\u4e0b\u9762\u662f\u8be6\u7ec6\u4ecb\u7ecd\u3002<\/p>\n<\/p>\n

\u4e00\u3001collections.Counter\u7c7b<\/h3>\n<\/p>\n

1\u3001\u5bfc\u5165Counter\u7c7b<\/h4>\n<\/p>\n

\u5728\u4f7f\u7528Counter\u7c7b\u4e4b\u524d\uff0c\u6211\u4eec\u9700\u8981\u5148\u5bfc\u5165collections\u6a21\u5757\u4e2d\u7684Counter\u7c7b\uff1a<\/p>\n<\/p>\n

from collections import Counter<\/p>\n
<\/code><\/pre>\n<\/p>\n
2\u3001\u521b\u5efaCounter\u5bf9\u8c61<\/h4>\n<\/p>\n
Counter\u5bf9\u8c61\u53ef\u4ee5\u901a\u8fc7\u4f20\u5165\u4e00\u4e2a\u53ef\u8fed\u4ee3\u5bf9\u8c61\u6765\u521b\u5efa\uff0c\u4f8b\u5982\u5217\u8868\u3001\u5b57\u7b26\u4e32\u7b49\u3002\u4e0b\u9762\u662f\u51e0\u4e2a\u4f8b\u5b50\uff1a<\/p>\n<\/p>\n
from collections import Counter<\/p>\n
\u521b\u5efaCounter\u5bf9\u8c61<\/strong><\/h2>\n
counter1 = Counter([1, 2, 2, 3, 3, 3])<\/p>\n
counter2 = Counter('abracadabra')<\/p>\n
counter3 = Counter({'apple': 2, 'banana': 3})<\/p>\n
counter4 = Counter(a=2, b=3)<\/p>\n
<\/code><\/pre>\n<\/p>\n
3\u3001\u8bbf\u95ee\u8ba1\u6570\u7ed3\u679c<\/h4>\n<\/p>\n
Counter\u5bf9\u8c61\u7684\u5143\u7d20\u8ba1\u6570\u7ed3\u679c\u53ef\u4ee5\u901a\u8fc7\u952e\u8bbf\u95ee\uff0c\u7c7b\u4f3c\u4e8e\u5b57\u5178\uff1a<\/p>\n<\/p>\n
print(counter1[1])  # \u8f93\u51fa\uff1a1<\/p>\n
print(counter2['a'])  # \u8f93\u51fa\uff1a5<\/p>\n
<\/code><\/pre>\n<\/p>\n
4\u3001\u66f4\u65b0\u8ba1\u6570\u5668<\/h4>\n<\/p>\n
\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528update\u65b9\u6cd5\u6765\u66f4\u65b0\u8ba1\u6570\u5668\uff0cupdate\u65b9\u6cd5\u53ef\u4ee5\u63a5\u53d7\u4e00\u4e2a\u53ef\u8fed\u4ee3\u5bf9\u8c61\u6216\u53e6\u4e00\u4e2aCounter\u5bf9\u8c61\uff1a<\/p>\n<\/p>\n
counter1.update([1, 2, 2, 3])<\/p>\n
print(counter1)  # \u8f93\u51fa\uff1aCounter({2: 4, 3: 4, 1: 2})<\/p>\n
<\/code><\/pre>\n<\/p>\n
5\u3001\u5143\u7d20\u8ba1\u6570\u51cf\u5c11<\/h4>\n<\/p>\n
subtract\u65b9\u6cd5\u53ef\u4ee5\u51cf\u5c11Counter\u5bf9\u8c61\u4e2d\u5143\u7d20\u7684\u8ba1\u6570\uff1a<\/p>\n<\/p>\n
counter1.subtract([2, 3])<\/p>\n
print(counter1)  # \u8f93\u51fa\uff1aCounter({3: 3, 2: 3, 1: 2})<\/p>\n
<\/code><\/pre>\n<\/p>\n
6\u3001\u6700\u5e38\u89c1\u7684\u5143\u7d20<\/h4>\n<\/p>\n
most_common\u65b9\u6cd5\u53ef\u4ee5\u8fd4\u56de\u8ba1\u6570\u6700\u591a\u7684n\u4e2a\u5143\u7d20\u53ca\u5176\u8ba1\u6570\uff1a<\/p>\n<\/p>\n
print(counter2.most_common(2))  # \u8f93\u51fa\uff1a[('a', 5), ('r', 2)]<\/p>\n
<\/code><\/pre>\n<\/p>\n
7\u3001\u5143\u7d20\u603b\u6570<\/h4>\n<\/p>\n
Counter\u5bf9\u8c61\u7684\u5143\u7d20\u603b\u6570\u53ef\u4ee5\u901a\u8fc7sum\u51fd\u6570\u548cvalues\u65b9\u6cd5\u8ba1\u7b97\u5f97\u5230\uff1a<\/p>\n<\/p>\n
total = sum(counter2.values())<\/p>\n
print(total)  # \u8f93\u51fa\uff1a11<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e8c\u3001\u4f7f\u7528\u5b57\u5178\u5b9e\u73b0\u8ba1\u6570\u5668<\/h3>\n<\/p>\n
\u867d\u7136Counter\u7c7b\u975e\u5e38\u65b9\u4fbf\uff0c\u4f46\u6211\u4eec\u4e5f\u53ef\u4ee5\u4f7f\u7528\u5b57\u5178\u6765\u5b9e\u73b0\u8ba1\u6570\u5668\u529f\u80fd\u3002\u8fd9\u79cd\u65b9\u6cd5\u9002\u5408\u4e0d\u4f9d\u8d56Counter\u7c7b\u7684\u573a\u666f\u3002<\/p>\n<\/p>\n
# \u4f7f\u7528\u5b57\u5178\u5b9e\u73b0\u8ba1\u6570\u5668<\/p>\n
data = [1, 2, 2, 3, 3, 3]<\/p>\n
counter = {}<\/p>\n
for item in data:<\/p>\n
    if item in counter:<\/p>\n
        counter[item] += 1<\/p>\n
    else:<\/p>\n
        counter[item] = 1<\/p>\n
print(counter)  # \u8f93\u51fa\uff1a{1: 1, 2: 2, 3: 3}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e09\u3001\u4f7f\u7528defaultdict\u5b9e\u73b0\u8ba1\u6570\u5668<\/h3>\n<\/p>\n
collections\u6a21\u5757\u4e2d\u7684defaultdict\u7c7b\u4e5f\u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u8ba1\u6570\u5668\u529f\u80fd\u3002defaultdict\u5141\u8bb8\u6211\u4eec\u4e3a\u5b57\u5178\u63d0\u4f9b\u4e00\u4e2a\u9ed8\u8ba4\u503c\u7c7b\u578b\uff0c\u5f53\u8bbf\u95ee\u4e0d\u5b58\u5728\u7684\u952e\u65f6\uff0c\u4f1a\u81ea\u52a8\u521b\u5efa\u4e00\u4e2a\u5177\u6709\u9ed8\u8ba4\u503c\u7684\u952e\u503c\u5bf9\u3002<\/p>\n<\/p>\n
from collections import defaultdict<\/p>\n
\u4f7f\u7528defaultdict\u5b9e\u73b0\u8ba1\u6570\u5668<\/strong><\/h2>\n
data = [1, 2, 2, 3, 3, 3]<\/p>\n
counter = defaultdict(int)<\/p>\n
for item in data:<\/p>\n
    counter[item] += 1<\/p>\n
print(counter)  # \u8f93\u51fa\uff1adefaultdict(<class 'int'>, {1: 1, 2: 2, 3: 3})<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u56db\u3001\u4f7f\u7528\u5217\u8868\u5b9e\u73b0\u8ba1\u6570\u5668<\/h3>\n<\/p>\n
\u5728\u67d0\u4e9b\u7279\u5b9a\u60c5\u51b5\u4e0b\uff0c\u6211\u4eec\u4e5f\u53ef\u4ee5\u4f7f\u7528\u5217\u8868\u6765\u5b9e\u73b0\u8ba1\u6570\u5668\u3002\u7279\u522b\u662f\u5f53\u6211\u4eec\u8981\u7edf\u8ba1\u7684\u5143\u7d20\u662f\u8fde\u7eed\u7684\u6574\u6570\u65f6\uff0c\u4f7f\u7528\u5217\u8868\u53ef\u4ee5\u66f4\u52a0\u9ad8\u6548\u3002<\/p>\n<\/p>\n
# \u4f7f\u7528\u5217\u8868\u5b9e\u73b0\u8ba1\u6570\u5668<\/p>\n
data = [1, 2, 2, 3, 3, 3]<\/p>\n
max_val = max(data)<\/p>\n
counter = [0] * (max_val + 1)<\/p>\n
for item in data:<\/p>\n
    counter[item] += 1<\/p>\n
print(counter)  # \u8f93\u51fa\uff1a[0, 1, 2, 3]<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e94\u3001\u7efc\u5408\u5b9e\u4f8b<\/h3>\n<\/p>\n
\u4e0b\u9762\u662f\u4e00\u4e2a\u7efc\u5408\u5b9e\u4f8b\uff0c\u5c55\u793a\u4e86\u5982\u4f55\u4f7f\u7528Counter\u7c7b\u7edf\u8ba1\u6587\u672c\u6587\u4ef6\u4e2d\u6bcf\u4e2a\u5355\u8bcd\u51fa\u73b0\u7684\u6b21\u6570\uff0c\u5e76\u627e\u51fa\u51fa\u73b0\u6b21\u6570\u6700\u591a\u7684\u524d10\u4e2a\u5355\u8bcd\u3002<\/p>\n<\/p>\n
from collections import Counter<\/p>\n
import re<\/p>\n
\u8bfb\u53d6\u6587\u672c\u6587\u4ef6<\/strong><\/h2>\n
with open('example.txt', 'r') as file:<\/p>\n
    text = file.read()<\/p>\n
\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\u5206\u5272\u5355\u8bcd<\/strong><\/h2>\n
words = re.findall(r'\\b\\w+\\b', text.lower())<\/p>\n
\u7edf\u8ba1\u5355\u8bcd\u51fa\u73b0\u7684\u6b21\u6570<\/strong><\/h2>\n
word_counter = Counter(words)<\/p>\n
\u83b7\u53d6\u51fa\u73b0\u6b21\u6570\u6700\u591a\u7684\u524d10\u4e2a\u5355\u8bcd<\/strong><\/h2>\n
most_common_words = word_counter.most_common(10)<\/p>\n
\u8f93\u51fa\u7ed3\u679c<\/strong><\/h2>\n
for word, count in most_common_words:<\/p>\n
    print(f'{word}: {count}')<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u8fd9\u4e2a\u5b9e\u4f8b\u4e2d\uff0c\u6211\u4eec\u9996\u5148\u8bfb\u53d6\u6587\u672c\u6587\u4ef6\u7684\u5185\u5bb9\uff0c\u5e76\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\u5c06\u6587\u672c\u5206\u5272\u6210\u5355\u8bcd\u3002\u7136\u540e\uff0c\u6211\u4eec\u4f7f\u7528Counter\u7c7b\u7edf\u8ba1\u6bcf\u4e2a\u5355\u8bcd\u51fa\u73b0\u7684\u6b21\u6570\uff0c\u6700\u540e\u8f93\u51fa\u51fa\u73b0\u6b21\u6570\u6700\u591a\u7684\u524d10\u4e2a\u5355\u8bcd\u53ca\u5176\u8ba1\u6570\u3002<\/p>\n<\/p>\n
\u901a\u8fc7\u4ee5\u4e0a\u51e0\u79cd\u65b9\u6cd5\uff0c\u6211\u4eec\u53ef\u4ee5\u7075\u6d3b\u5730\u5728Python\u4e2d\u5b9e\u73b0\u8ba1\u6570\u5668\u529f\u80fd\u3002collections.Counter\u7c7b\u662f\u6700\u63a8\u8350\u7684\u65b9\u6cd5\uff0c\u56e0\u4e3a\u5b83\u4f7f\u7528\u7b80\u5355\u3001\u529f\u80fd\u5f3a\u5927\uff0c\u9002\u7528\u4e8e\u5927\u591a\u6570\u8ba1\u6570\u9700\u6c42<\/strong>\u3002\u4f46\u5728\u4e00\u4e9b\u7279\u5b9a\u573a\u666f\u4e0b\uff0c\u4f7f\u7528\u5b57\u5178\u3001defaultdict\u6216\u5217\u8868\u4e5f\u80fd\u5b9e\u73b0\u8ba1\u6570\u5668\u529f\u80fd\uff0c\u5e76\u4e14\u53ef\u80fd\u66f4\u52a0\u9ad8\u6548\u3002\u5e0c\u671b\u8fd9\u7bc7\u6587\u7ae0\u80fd\u5e2e\u52a9\u4f60\u66f4\u597d\u5730\u7406\u89e3\u548c\u4f7f\u7528Python\u4e2d\u7684\u8ba1\u6570\u5668\u3002<\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
 Python\u4e2d\u7684\u8ba1\u6570\u5668\u662f\u4ec0\u4e48\uff1f\u5b83\u6709\u4ec0\u4e48\u7528\u9014\uff1f<\/strong>
\u8ba1\u6570\u5668\u662fPython collections\u6a21\u5757\u4e2d\u7684\u4e00\u4e2a\u5b50\u7c7b\uff0c\u4e3b\u8981\u7528\u4e8e\u7edf\u8ba1\u53ef\u54c8\u5e0c\u5bf9\u8c61\u7684\u51fa\u73b0\u6b21\u6570\u3002\u8ba1\u6570\u5668\u7684\u4e3b\u8981\u7528\u9014\u5305\u62ec\u7edf\u8ba1\u5b57\u7b26\u4e32\u4e2d\u5b57\u7b26\u7684\u9891\u7387\u3001\u5728\u6570\u636e\u5206\u6790\u4e2d\u8ba1\u7b97\u503c\u7684\u51fa\u73b0\u9891\u7387\uff0c\u4ee5\u53ca\u5728\u6e38\u620f\u5f00\u53d1\u4e2d\u8bb0\u5f55\u73a9\u5bb6\u7684\u5206\u6570\u7b49\u3002\u901a\u8fc7\u4f7f\u7528\u8ba1\u6570\u5668\uff0c\u53ef\u4ee5\u8f7b\u677e\u5730\u5904\u7406\u548c\u5206\u6790\u6570\u636e\uff0c\u4f7f\u5f97\u7f16\u7a0b\u66f4\u52a0\u9ad8\u6548\u3002<\/p>\n
\u5982\u4f55\u521b\u5efa\u4e00\u4e2a\u8ba1\u6570\u5668\u5e76\u6dfb\u52a0\u5143\u7d20\uff1f<\/strong>
\u5728Python\u4e2d\uff0c\u521b\u5efa\u8ba1\u6570\u5668\u975e\u5e38\u7b80\u5355\u3002\u53ea\u9700\u5bfc\u5165collections<\/code>\u6a21\u5757\u4e2d\u7684Counter<\/code>\u7c7b\uff0c\u5e76\u4f20\u5165\u4e00\u4e2a\u53ef\u8fed\u4ee3\u5bf9\u8c61\uff0c\u6bd4\u5982\u5217\u8868\u6216\u5b57\u7b26\u4e32\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a  <\/p>\n
from collections import Counter\nmy_counter = Counter(['a', 'b', 'a', 'c', 'b', 'a'])\nprint(my_counter)  # \u8f93\u51fa\uff1aCounter({'a': 3, 'b': 2, 'c': 1})\n<\/code><\/pre>\n
\u8fd9\u6bb5\u4ee3\u7801\u521b\u5efa\u4e86\u4e00\u4e2a\u8ba1\u6570\u5668\uff0c\u7edf\u8ba1\u4e86\u5b57\u7b26'a'\u3001'b'\u548c'c'\u7684\u51fa\u73b0\u6b21\u6570\u3002<\/p>\n
\u5982\u4f55\u4ece\u8ba1\u6570\u5668\u4e2d\u83b7\u53d6\u6700\u5e38\u89c1\u7684\u5143\u7d20\uff1f<\/strong>
\u8981\u83b7\u53d6\u8ba1\u6570\u5668\u4e2d\u6700\u5e38\u89c1\u7684\u5143\u7d20\uff0c\u53ef\u4ee5\u4f7f\u7528most_common()<\/code>\u65b9\u6cd5\u3002\u8fd9\u4e2a\u65b9\u6cd5\u8fd4\u56de\u4e00\u4e2a\u5305\u542b\u5143\u7d20\u53ca\u5176\u8ba1\u6570\u7684\u5217\u8868\uff0c\u6309\u51fa\u73b0\u9891\u7387\u964d\u5e8f\u6392\u5217\u3002\u4f8b\u5982\uff1a  <\/p>\n
most_common_elements = my_counter.most_common(2)\nprint(most_common_elements)  # \u8f93\u51fa\uff1a [('a', 3), ('b', 2)]\n<\/code><\/pre>\n
\u901a\u8fc7\u8fd9\u79cd\u65b9\u5f0f\uff0c\u5f00\u53d1\u8005\u53ef\u4ee5\u5feb\u901f\u627e\u51fa\u6570\u636e\u96c6\u4e2d\u51fa\u73b0\u9891\u7387\u6700\u9ad8\u7684\u5143\u7d20\uff0c\u4fbf\u4e8e\u540e\u7eed\u7684\u6570\u636e\u5904\u7406\u548c\u5206\u6790\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"Python\u4e2d\u4f7f\u7528\u8ba1\u6570\u5668\u7684\u65b9\u6cd5\u5305\u62ec\u4f7f\u7528collections.Counter\u7c7b\u3001\u4f7f\u7528\u5b57\u5178\u3001\u4f7f\u7528defaultd […]","protected":false},"author":3,"featured_media":1091114,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1091108"}],"collection":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/comments?post=1091108"}],"version-history":[{"count":"1","href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1091108\/revisions"}],"predecessor-version":[{"id":1091121,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1091108\/revisions\/1091121"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/1091114"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=1091108"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=1091108"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=1091108"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}