{"id":1156294,"date":"2025-01-13T18:14:13","date_gmt":"2025-01-13T10:14:13","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/1156294.html"},"modified":"2025-01-13T18:14:15","modified_gmt":"2025-01-13T10:14:15","slug":"python%e5%a6%82%e4%bd%95%e8%be%93%e5%87%ba%e5%87%a0%e4%bd%8d%e5%b0%8f%e6%95%b0","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/1156294.html","title":{"rendered":"python\u5982\u4f55\u8f93\u51fa\u51e0\u4f4d\u5c0f\u6570"},"content":{"rendered":"

\"python\u5982\u4f55\u8f93\u51fa\u51e0\u4f4d\u5c0f\u6570\"<\/p>\n

\u4f7f\u7528Python\u8f93\u51fa\u51e0\u4f4d\u5c0f\u6570\u7684\u65b9\u6cd5\u6709\u591a\u79cd\uff1a\u4f7f\u7528round\u51fd\u6570\u3001\u4f7f\u7528\u5b57\u7b26\u4e32\u683c\u5f0f\u5316\uff08\u5982f-string\u3001format\u65b9\u6cd5\uff09\u3001\u4f7f\u7528decimal\u6a21\u5757\u7b49\u3002<\/strong>\u5728\u8fd9\u91cc\uff0c\u6211\u4eec\u5c06\u8be6\u7ec6\u63a2\u8ba8\u5176\u4e2d\u4e00\u79cd\u65b9\u6cd5\uff0c\u5373\u4f7f\u7528\u5b57\u7b26\u4e32\u683c\u5f0f\u5316\uff08f-string\uff09\u6765\u8fdb\u884c\u8f93\u51fa\u51e0\u4f4d\u5c0f\u6570\u3002<\/p>\n<\/p>\n

\u4e00\u3001\u4f7f\u7528round\u51fd\u6570<\/h3>\n<\/p>\n

round()<\/code>\u51fd\u6570\u662fPython\u5185\u7f6e\u7684\u51fd\u6570\uff0c\u7528\u4e8e\u5c06\u6570\u5b57\u56db\u820d\u4e94\u5165\u5230\u6307\u5b9a\u7684\u5c0f\u6570\u4f4d\u6570\u3002\u5b83\u6709\u4e24\u4e2a\u53c2\u6570\uff1a\u4e00\u4e2a\u662f\u8981\u56db\u820d\u4e94\u5165\u7684\u6570\u5b57\uff0c\u53e6\u4e00\u4e2a\u662f\u8981\u4fdd\u7559\u7684\u5c0f\u6570\u4f4d\u6570\u3002\u4f8b\u5982\uff0cround(3.14159, 2)<\/code>\u5c06\u8fd4\u56de3.14\u3002<\/p>\n<\/p>\n

num = 3.14159<\/p>\n
rounded_num = round(num, 2)<\/p>\n
print(rounded_num)  # \u8f93\u51fa\uff1a3.14<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e8c\u3001\u4f7f\u7528\u5b57\u7b26\u4e32\u683c\u5f0f\u5316<\/h3>\n<\/p>\n
1\u3001\u4f7f\u7528f-string<\/h4>\n<\/p>\n
f-string\u662fPython 3.6\u5f15\u5165\u7684\u4e00\u79cd\u65b0\u7684\u5b57\u7b26\u4e32\u683c\u5f0f\u5316\u65b9\u6cd5\u3002\u5b83\u5728\u5b57\u7b26\u4e32\u524d\u6dfb\u52a0\u4e00\u4e2a\u5b57\u6bcdf<\/code>\uff0c\u5e76\u4f7f\u7528\u5927\u62ec\u53f7{}<\/code>\u6765\u5305\u542b\u8868\u8fbe\u5f0f\u3002\u8981\u63a7\u5236\u5c0f\u6570\u4f4d\u6570\uff0c\u53ef\u4ee5\u5728\u5927\u62ec\u53f7\u5185\u4f7f\u7528\u683c\u5f0f\u8bf4\u660e\u7b26\u3002\u4f8b\u5982\uff0c{value:.2f}<\/code>\u8868\u793a\u5c06value\u683c\u5f0f\u5316\u4e3a\u4fdd\u7559\u4e24\u4f4d\u5c0f\u6570\u7684\u6d6e\u70b9\u6570\u3002<\/p>\n<\/p>\n
num = 3.14159<\/p>\n
formatted_num = f"{num:.2f}"<\/p>\n
print(formatted_num)  # \u8f93\u51fa\uff1a3.14<\/p>\n
<\/code><\/pre>\n<\/p>\n
2\u3001\u4f7f\u7528format\u65b9\u6cd5<\/h4>\n<\/p>\n
format()<\/code>\u65b9\u6cd5\u662fPython 2.7\u548c3.0\u5f15\u5165\u7684\u4e00\u79cd\u5b57\u7b26\u4e32\u683c\u5f0f\u5316\u65b9\u6cd5\u3002\u5b83\u4f7f\u7528\u5927\u62ec\u53f7{}<\/code>\u6765\u8868\u793a\u66ff\u6362\u5b57\u6bb5\uff0c\u5e76\u5728\u5927\u62ec\u53f7\u5185\u4f7f\u7528\u683c\u5f0f\u8bf4\u660e\u7b26\u3002\u4f8b\u5982\uff0c{:.2f}<\/code>\u8868\u793a\u5c06\u683c\u5f0f\u5316\u4e3a\u4fdd\u7559\u4e24\u4f4d\u5c0f\u6570\u7684\u6d6e\u70b9\u6570\u3002<\/p>\n<\/p>\n
num = 3.14159<\/p>\n
formatted_num = "{:.2f}".format(num)<\/p>\n
print(formatted_num)  # \u8f93\u51fa\uff1a3.14<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e09\u3001\u4f7f\u7528decimal\u6a21\u5757<\/h3>\n<\/p>\n
decimal<\/code>\u6a21\u5757\u63d0\u4f9b\u4e86\u4e00\u4e2aDecimal<\/code>\u6570\u636e\u7c7b\u578b\uff0c\u7528\u4e8e\u8fdb\u884c\u9ad8\u7cbe\u5ea6\u7684\u5341\u8fdb\u5236\u6d6e\u70b9\u8fd0\u7b97\u3002\u5b83\u53ef\u4ee5\u66f4\u7cbe\u786e\u5730\u63a7\u5236\u5c0f\u6570\u4f4d\u6570\u548c\u56db\u820d\u4e94\u5165\u7684\u884c\u4e3a\u3002<\/p>\n<\/p>\n
from decimal import Decimal, ROUND_HALF_UP<\/p>\n
num = Decimal("3.14159")<\/p>\n
rounded_num = num.quantize(Decimal("0.01"), rounding=ROUND_HALF_UP)<\/p>\n
print(rounded_num)  # \u8f93\u51fa\uff1a3.14<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u56db\u3001\u5e94\u7528\u573a\u666f\u548c\u6ce8\u610f\u4e8b\u9879<\/h3>\n<\/p>\n
1\u3001\u91d1\u878d\u8ba1\u7b97<\/h4>\n<\/p>\n
\u5728\u91d1\u878d\u8ba1\u7b97\u4e2d\uff0c\u7cbe\u5ea6\u975e\u5e38\u91cd\u8981\u3002\u4f7f\u7528\u6d6e\u70b9\u6570\u53ef\u80fd\u4f1a\u5f15\u8d77\u7cbe\u5ea6\u95ee\u9898\uff0c\u56e0\u6b64\u5efa\u8bae\u4f7f\u7528decimal<\/code>\u6a21\u5757\u3002\u4f8b\u5982\uff0c\u5728\u8ba1\u7b97\u5229\u606f\u65f6\uff0c\u4f7f\u7528Decimal<\/code>\u7c7b\u578b\u53ef\u4ee5\u786e\u4fdd\u7ed3\u679c\u7684\u7cbe\u5ea6\u3002<\/p>\n<\/p>\n
from decimal import Decimal<\/p>\n
principal = Decimal("1000.00")<\/p>\n
rate = Decimal("0.05")<\/p>\n
interest = principal * rate<\/p>\n
print(interest.quantize(Decimal("0.01")))  # \u8f93\u51fa\uff1a50.00<\/p>\n
<\/code><\/pre>\n<\/p>\n
2\u3001\u79d1\u5b66\u8ba1\u7b97<\/h4>\n<\/p>\n
\u5728\u79d1\u5b66\u8ba1\u7b97\u4e2d\uff0c\u901a\u5e38\u9700\u8981\u9ad8\u7cbe\u5ea6\u7684\u6d6e\u70b9\u6570\u3002\u4f8b\u5982\uff0c\u5728\u8ba1\u7b97\u5706\u5468\u7387\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528Decimal<\/code>\u7c7b\u578b\u6765\u786e\u4fdd\u7ed3\u679c\u7684\u7cbe\u5ea6\u3002<\/p>\n<\/p>\n
from decimal import Decimal, getcontext<\/p>\n
getcontext().prec = 50<\/p>\n
pi = Decimal("3.14159265358979323846264338327950288419716939937510")<\/p>\n
print(pi)  # \u8f93\u51fa\uff1a3.14159265358979323846264338327950288419716939937510<\/p>\n
<\/code><\/pre>\n<\/p>\n
3\u3001\u6570\u636e\u5c55\u793a<\/h4>\n<\/p>\n
\u5728\u6570\u636e\u5c55\u793a\u4e2d\uff0c\u901a\u5e38\u9700\u8981\u63a7\u5236\u5c0f\u6570\u4f4d\u6570\u4ee5\u786e\u4fdd\u6570\u636e\u7684\u53ef\u8bfb\u6027\u3002\u4f8b\u5982\uff0c\u5728\u663e\u793a\u4ef7\u683c\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528round()<\/code>\u51fd\u6570\u6765\u63a7\u5236\u5c0f\u6570\u4f4d\u6570\u3002<\/p>\n<\/p>\n
price = 19.999<\/p>\n
print(f"Price: ${round(price, 2)}")  # \u8f93\u51fa\uff1aPrice: $20.0<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e94\u3001\u6027\u80fd\u6bd4\u8f83<\/h3>\n<\/p>\n
\u5728\u9009\u62e9\u5c0f\u6570\u4f4d\u6570\u5904\u7406\u65b9\u6cd5\u65f6\uff0c\u6027\u80fd\u4e5f\u662f\u4e00\u4e2a\u9700\u8981\u8003\u8651\u7684\u56e0\u7d20\u3002\u4e00\u822c\u6765\u8bf4\uff0c\u5185\u7f6e\u51fd\u6570round()<\/code>\u548c\u5b57\u7b26\u4e32\u683c\u5f0f\u5316\u65b9\u6cd5\uff08\u5982f-string\u548cformat()<\/code>\uff09\u7684\u6027\u80fd\u8f83\u597d\uff0c\u800cdecimal<\/code>\u6a21\u5757\u7684\u6027\u80fd\u8f83\u5dee\uff0c\u4f46\u5176\u63d0\u4f9b\u4e86\u66f4\u9ad8\u7684\u7cbe\u5ea6\u548c\u66f4\u591a\u7684\u529f\u80fd\u3002<\/p>\n<\/p>\n
\u53ef\u4ee5\u901a\u8fc7\u4ee5\u4e0b\u4ee3\u7801\u8fdb\u884c\u7b80\u5355\u7684\u6027\u80fd\u6bd4\u8f83\uff1a<\/p>\n<\/p>\n
import timeit<\/p>\n
num = 3.14159<\/p>\n
round\u51fd\u6570<\/strong><\/h2>\n
print(timeit.timeit("round(num, 2)", setup="from __mAI<\/a>n__ import num", number=1000000))<\/p>\n
f-string<\/strong><\/h2>\n
print(timeit.timeit('f"{num:.2f}"', setup="from __main__ import num", number=1000000))<\/p>\n
format\u65b9\u6cd5<\/strong><\/h2>\n
print(timeit.timeit('"{:.2f}".format(num)', setup="from __main__ import num", number=1000000))<\/p>\n
decimal\u6a21\u5757<\/strong><\/h2>\n
from decimal import Decimal<\/p>\n
num_decimal = Decimal("3.14159")<\/p>\n
print(timeit.timeit('num_decimal.quantize(Decimal("0.01"))', setup="from __main__ import num_decimal, Decimal", number=1000000))<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u901a\u8fc7\u8fd0\u884c\u4e0a\u8ff0\u4ee3\u7801\uff0c\u53ef\u4ee5\u83b7\u5f97\u4e0d\u540c\u65b9\u6cd5\u7684\u6027\u80fd\u6570\u636e\uff0c\u4ece\u800c\u9009\u62e9\u9002\u5408\u81ea\u5df1\u9700\u6c42\u7684\u65b9\u6cd5\u3002<\/p>\n<\/p>\n
\u516d\u3001\u603b\u7ed3<\/h3>\n<\/p>\n
\u5728Python\u4e2d\uff0c\u8f93\u51fa\u51e0\u4f4d\u5c0f\u6570\u7684\u65b9\u6cd5\u6709\u591a\u79cd\uff0c\u5305\u62ec\u4f7f\u7528round()<\/code>\u51fd\u6570\u3001\u5b57\u7b26\u4e32\u683c\u5f0f\u5316\uff08\u5982f-string\u548cformat()<\/code>\u65b9\u6cd5\uff09\u548cdecimal<\/code>\u6a21\u5757\u3002\u4e0d\u540c\u65b9\u6cd5\u6709\u4e0d\u540c\u7684\u5e94\u7528\u573a\u666f\u548c\u6027\u80fd\u7279\u70b9\uff0c\u9009\u62e9\u9002\u5408\u81ea\u5df1\u9700\u6c42\u7684\u65b9\u6cd5\u975e\u5e38\u91cd\u8981\u3002\u5bf9\u4e8e\u5927\u591a\u6570\u573a\u666f\uff0cf-string\u548cformat()<\/code>\u65b9\u6cd5\u662f\u8f83\u4e3a\u63a8\u8350\u7684\u9009\u62e9\uff0c\u56e0\u4e3a\u5b83\u4eec\u7b80\u6d01\u3001\u6613\u7528\u4e14\u6027\u80fd\u8f83\u597d\u3002<\/strong>\u7136\u800c\uff0c\u5728\u9700\u8981\u9ad8\u7cbe\u5ea6\u8ba1\u7b97\u7684\u573a\u666f\u4e0b\uff0cdecimal<\/code>\u6a21\u5757\u662f\u66f4\u4e3a\u5408\u9002\u7684\u9009\u62e9\u3002<\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
 \u5982\u4f55\u5728Python\u4e2d\u683c\u5f0f\u5316\u6d6e\u70b9\u6570\u4ee5\u8f93\u51fa\u7279\u5b9a\u7684\u5c0f\u6570\u4f4d\u6570\uff1f<\/strong>
\u5728Python\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u683c\u5f0f\u5316\u5b57\u7b26\u4e32\u6216\u5185\u7f6e\u7684round()<\/code>\u51fd\u6570\u6765\u63a7\u5236\u8f93\u51fa\u7684\u6d6e\u70b9\u6570\u5c0f\u6570\u4f4d\u6570\u3002\u4f7f\u7528\u683c\u5f0f\u5316\u5b57\u7b26\u4e32\uff0c\u53ef\u4ee5\u901a\u8fc7f-string<\/code>\u6216\u8005format()<\/code>\u65b9\u6cd5\u6765\u5b9e\u73b0\u3002\u4f8b\u5982\uff0c\u4f7f\u7528f"{value:.2f}"<\/code>\u53ef\u4ee5\u5c06\u6d6e\u70b9\u6570\u683c\u5f0f\u5316\u4e3a\u4e24\u4f4d\u5c0f\u6570\u3002\u7c7b\u4f3c\u5730\uff0c"{:.2f}".format(value)<\/code>\u4e5f\u80fd\u8fbe\u5230\u76f8\u540c\u6548\u679c\u3002<\/p>\n
\u5728Python\u4e2d\uff0c\u5982\u4f55\u5c06\u5c0f\u6570\u56db\u820d\u4e94\u5165\u5230\u6307\u5b9a\u7684\u5c0f\u6570\u4f4d\u6570\uff1f<\/strong>
\u4f7f\u7528round()<\/code>\u51fd\u6570\u53ef\u4ee5\u8f7b\u677e\u5b9e\u73b0\u56db\u820d\u4e94\u5165\u3002\u8be5\u51fd\u6570\u63a5\u53d7\u4e24\u4e2a\u53c2\u6570\uff0c\u7b2c\u4e00\u4e2a\u662f\u8981\u5904\u7406\u7684\u6d6e\u70b9\u6570\uff0c\u7b2c\u4e8c\u4e2a\u662f\u8981\u4fdd\u7559\u7684\u5c0f\u6570\u4f4d\u6570\u3002\u4f8b\u5982\uff0cround(value, 2)<\/code>\u4f1a\u5c06value<\/code>\u56db\u820d\u4e94\u5165\u5230\u4e24\u4f4d\u5c0f\u6570\u3002<\/p>\n
\u5728Python\u4e2d\uff0c\u5982\u4f55\u5904\u7406\u6d6e\u70b9\u6570\u7684\u7cbe\u5ea6\u95ee\u9898\uff1f<\/strong>
\u6d6e\u70b9\u6570\u7684\u7cbe\u5ea6\u95ee\u9898\u5728Python\u4e2d\u662f\u5e38\u89c1\u7684\uff0c\u5c24\u5176\u662f\u5728\u8fdb\u884c\u591a\u6b21\u8fd0\u7b97\u65f6\u3002\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u53ef\u4ee5\u8003\u8651\u4f7f\u7528decimal<\/code>\u6a21\u5757\uff0c\u8be5\u6a21\u5757\u63d0\u4f9b\u4e86\u66f4\u9ad8\u7cbe\u5ea6\u7684\u6d6e\u70b9\u8fd0\u7b97\u3002\u4f7f\u7528from decimal import Decimal<\/code>\uff0c\u7136\u540e\u5c06\u6d6e\u70b9\u6570\u8f6c\u6362\u4e3aDecimal<\/code>\u7c7b\u578b\uff0c\u53ef\u4ee5\u6709\u6548\u907f\u514d\u7cbe\u5ea6\u4e22\u5931\u7684\u95ee\u9898\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"\u4f7f\u7528Python\u8f93\u51fa\u51e0\u4f4d\u5c0f\u6570\u7684\u65b9\u6cd5\u6709\u591a\u79cd\uff1a\u4f7f\u7528round\u51fd\u6570\u3001\u4f7f\u7528\u5b57\u7b26\u4e32\u683c\u5f0f\u5316\uff08\u5982f-string\u3001forma […]","protected":false},"author":3,"featured_media":1156302,"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\/1156294"}],"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=1156294"}],"version-history":[{"count":"1","href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1156294\/revisions"}],"predecessor-version":[{"id":1156303,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1156294\/revisions\/1156303"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/1156302"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=1156294"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=1156294"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=1156294"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}