{"id":1156510,"date":"2025-01-13T18:17:01","date_gmt":"2025-01-13T10:17:01","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/1156510.html"},"modified":"2025-01-13T18:17:04","modified_gmt":"2025-01-13T10:17:04","slug":"python%e5%ad%97%e5%85%b8%e5%a6%82%e4%bd%95%e5%8a%a0%e5%85%a5%e5%85%83%e7%b4%a0","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/1156510.html","title":{"rendered":"python\u5b57\u5178\u5982\u4f55\u52a0\u5165\u5143\u7d20"},"content":{"rendered":"

\"python\u5b57\u5178\u5982\u4f55\u52a0\u5165\u5143\u7d20\"<\/p>\n

\u8981\u5728Python\u5b57\u5178\u4e2d\u52a0\u5165\u5143\u7d20\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528\u76f4\u63a5\u8d4b\u503c\u3001update()\u65b9\u6cd5\u3001fromkeys()\u65b9\u6cd5<\/strong>\u3002\u5176\u4e2d\uff0c\u76f4\u63a5\u8d4b\u503c<\/strong>\u662f\u6700\u5e38\u7528\u548c\u6700\u7b80\u5355\u7684\u65b9\u6cd5\u3002\u4f60\u53ef\u4ee5\u901a\u8fc7\u952e\u6765\u6dfb\u52a0\u6216\u66f4\u65b0\u5b57\u5178\u4e2d\u7684\u503c\u3002\u6bd4\u5982\uff0c\u901a\u8fc7\u76f4\u63a5\u8d4b\u503c\u7684\u65b9\u6cd5\uff0c\u4f7f\u7528\u952e\u4f5c\u4e3a\u7d22\u5f15\u6765\u6dfb\u52a0\u5143\u7d20\uff0c\u5982\u679c\u952e\u5df2\u7ecf\u5b58\u5728\uff0c\u5219\u66f4\u65b0\u5176\u503c\u3002\u5982\u679c\u952e\u4e0d\u5b58\u5728\uff0c\u5219\u65b0\u589e\u4e00\u4e2a\u952e\u503c\u5bf9\u3002\u4e0b\u9762\u6211\u4eec\u5c06\u8be6\u7ec6\u63a2\u8ba8\u8fd9\u4e9b\u65b9\u6cd5\uff0c\u5e76\u63d0\u4f9b\u4e00\u4e9b\u793a\u4f8b\u4ee3\u7801\u4ee5\u5e2e\u52a9\u7406\u89e3\u3002<\/p>\n<\/p>\n

\u4e00\u3001\u76f4\u63a5\u8d4b\u503c<\/p>\n

\u76f4\u63a5\u8d4b\u503c\u662f\u6700\u5e38\u89c1\u7684\u65b9\u6cd5\u3002\u4f60\u53ef\u4ee5\u901a\u8fc7\u5b57\u5178\u540d[key] = value\u7684\u65b9\u5f0f\u6765\u6dfb\u52a0\u6216\u66f4\u65b0\u5143\u7d20\u3002\u5982\u679ckey\u5df2\u7ecf\u5b58\u5728\uff0c\u5219\u66f4\u65b0\u5176\u503c\uff1b\u5982\u679ckey\u4e0d\u5b58\u5728\uff0c\u5219\u65b0\u589e\u4e00\u4e2a\u952e\u503c\u5bf9\u3002<\/p>\n<\/p>\n

my_dict = {'name': 'Alice', 'age': 25}<\/p>\n
my_dict['address'] = '123 MAI<\/a>n St'  # \u6dfb\u52a0\u65b0\u5143\u7d20<\/p>\n
my_dict['age'] = 26  # \u66f4\u65b0\u5df2\u6709\u5143\u7d20<\/p>\n
print(my_dict)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0cmy_dict<\/code>\u6700\u521d\u5305\u542b\u4e24\u4e2a\u952e\u503c\u5bf9\u3002\u901a\u8fc7my_dict['address'] = '123 Main St'<\/code>\uff0c\u6211\u4eec\u6dfb\u52a0\u4e86\u4e00\u4e2a\u65b0\u7684\u952e\u503c\u5bf9\u3002\u901a\u8fc7my_dict['age'] = 26<\/code>\uff0c\u6211\u4eec\u66f4\u65b0\u4e86\u5df2\u6709\u7684\u952e\u503c\u5bf9\u3002<\/p>\n<\/p>\n
\u4e8c\u3001update()\u65b9\u6cd5<\/p>\n
update()<\/code>\u65b9\u6cd5\u53ef\u4ee5\u4e00\u6b21\u6027\u6dfb\u52a0\u6216\u66f4\u65b0\u591a\u4e2a\u952e\u503c\u5bf9\u3002\u8be5\u65b9\u6cd5\u63a5\u53d7\u4e00\u4e2a\u5b57\u5178\u6216\u53ef\u8fed\u4ee3\u7684\u952e\u503c\u5bf9\u4f5c\u4e3a\u53c2\u6570\uff0c\u5e76\u5c06\u8fd9\u4e9b\u952e\u503c\u5bf9\u6dfb\u52a0\u5230\u539f\u5b57\u5178\u4e2d\u3002<\/p>\n<\/p>\n
my_dict = {'name': 'Alice', 'age': 25}<\/p>\n
my_dict.update({'address': '123 Main St', 'age': 26})  # \u6dfb\u52a0\u6216\u66f4\u65b0\u591a\u4e2a\u5143\u7d20<\/p>\n
print(my_dict)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u901a\u8fc7update()<\/code>\u65b9\u6cd5\uff0c\u6211\u4eec\u540c\u65f6\u6dfb\u52a0\u4e86address<\/code>\u952e\uff0c\u5e76\u66f4\u65b0\u4e86age<\/code>\u952e\u3002<\/p>\n<\/p>\n
\u4e09\u3001fromkeys()\u65b9\u6cd5<\/p>\n
fromkeys()<\/code>\u65b9\u6cd5\u7528\u4e8e\u521b\u5efa\u4e00\u4e2a\u65b0\u5b57\u5178\uff0c\u5e76\u5c06\u6307\u5b9a\u7684\u952e\u503c\u5bf9\u6dfb\u52a0\u5230\u8be5\u5b57\u5178\u4e2d\u3002\u4f60\u53ef\u4ee5\u6307\u5b9a\u4e00\u4e2a\u9ed8\u8ba4\u503c\u7ed9\u6240\u6709\u7684\u952e\u3002<\/p>\n<\/p>\n
keys = ['name', 'age', 'address']<\/p>\n
default_value = None<\/p>\n
new_dict = dict.fromkeys(keys, default_value)<\/p>\n
print(new_dict)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u6211\u4eec\u4f7f\u7528fromkeys()<\/code>\u65b9\u6cd5\u521b\u5efa\u4e86\u4e00\u4e2a\u5305\u542b\u6307\u5b9a\u952e\u7684\u5b57\u5178\uff0c\u5e76\u4e3a\u6240\u6709\u7684\u952e\u8d4b\u4e88\u9ed8\u8ba4\u503cNone<\/code>\u3002<\/p>\n<\/p>\n
\n
\u56db\u3001\u4f7f\u7528setdefault()\u65b9\u6cd5<\/p>\n
setdefault()<\/code>\u65b9\u6cd5\u7528\u4e8e\u5728\u5b57\u5178\u4e2d\u63d2\u5165\u4e00\u4e2a\u952e\u503c\u5bf9\uff0c\u5982\u679c\u952e\u5df2\u7ecf\u5b58\u5728\uff0c\u5219\u8fd4\u56de\u5176\u503c\uff0c\u4e0d\u505a\u4efb\u4f55\u4fee\u6539\uff1b\u5982\u679c\u952e\u4e0d\u5b58\u5728\uff0c\u5219\u63d2\u5165\u952e\u503c\u5bf9\uff0c\u5e76\u8fd4\u56de\u8be5\u503c\u3002<\/p>\n<\/p>\n
my_dict = {'name': 'Alice', 'age': 25}<\/p>\n
result = my_dict.setdefault('address', '123 Main St')  # \u6dfb\u52a0\u65b0\u5143\u7d20<\/p>\n
print(result)  # \u8f93\u51fa: 123 Main St<\/p>\n
print(my_dict)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u901a\u8fc7setdefault()<\/code>\u65b9\u6cd5\uff0c\u6211\u4eec\u6dfb\u52a0\u4e86\u4e00\u4e2a\u65b0\u7684\u952e\u503c\u5bf9\uff0c\u5e76\u8fd4\u56de\u4e86\u65b0\u63d2\u5165\u7684\u503c\u3002<\/p>\n<\/p>\n
\u4e94\u3001\u4f7f\u7528\u5b57\u5178\u63a8\u5bfc\u5f0f<\/p>\n
\u5b57\u5178\u63a8\u5bfc\u5f0f\u662f\u4e00\u79cd\u7b80\u6d01\u7684\u521b\u5efa\u5b57\u5178\u7684\u65b9\u5f0f\u3002\u4f60\u53ef\u4ee5\u4f7f\u7528\u5b57\u5178\u63a8\u5bfc\u5f0f\u6765\u6dfb\u52a0\u6216\u66f4\u65b0\u5b57\u5178\u4e2d\u7684\u5143\u7d20\u3002<\/p>\n<\/p>\n
my_dict = {'name': 'Alice', 'age': 25}<\/p>\n
new_entries = {'address': '123 Main St', 'job': 'Engineer'}<\/p>\n
my_dict = {<strong>my_dict, <\/strong>new_entries}<\/p>\n
print(my_dict)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u6211\u4eec\u4f7f\u7528\u5b57\u5178\u63a8\u5bfc\u5f0f\u5c06new_entries<\/code>\u4e2d\u7684\u952e\u503c\u5bf9\u6dfb\u52a0\u5230\u4e86my_dict<\/code>\u4e2d\u3002<\/p>\n<\/p>\n
\u516d\u3001\u4f7f\u7528collections.defaultdict<\/p>\n
defaultdict<\/code>\u662fcollections<\/code>\u6a21\u5757\u4e2d\u7684\u4e00\u4e2a\u7c7b\uff0c\u5b83\u53ef\u4ee5\u4e3a\u5b57\u5178\u4e2d\u7684\u952e\u63d0\u4f9b\u9ed8\u8ba4\u503c\u3002\u4f7f\u7528defaultdict<\/code>\u53ef\u4ee5\u66f4\u65b9\u4fbf\u5730\u6dfb\u52a0\u65b0\u5143\u7d20\u3002<\/p>\n<\/p>\n
from collections import defaultdict<\/p>\n
my_dict = defaultdict(lambda: 'N\/A')<\/p>\n
my_dict['name'] = 'Alice'<\/p>\n
my_dict['age'] = 25<\/p>\n
print(my_dict['address'])  # \u8f93\u51fa: N\/A<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u901a\u8fc7defaultdict<\/code>\uff0c\u6211\u4eec\u4e3a\u5b57\u5178\u63d0\u4f9b\u4e86\u4e00\u4e2a\u9ed8\u8ba4\u503c\uff0c\u5f53\u8bbf\u95ee\u4e0d\u5b58\u5728\u7684\u952e\u65f6\uff0c\u5c06\u8fd4\u56de\u9ed8\u8ba4\u503cN\/A<\/code>\u3002<\/p>\n<\/p>\n
\u4e03\u3001\u4f7f\u7528\u5b57\u5178\u7684union\u64cd\u4f5c\uff08Python 3.9+\uff09<\/p>\n
\u5728Python 3.9\u53ca\u66f4\u9ad8\u7248\u672c\u4e2d\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528\u5b57\u5178\u7684|<\/code>\uff08\u8054\u5408\uff09\u64cd\u4f5c\u7b26\u6765\u5408\u5e76\u5b57\u5178\uff0c\u4ece\u800c\u6dfb\u52a0\u65b0\u5143\u7d20\u3002<\/p>\n<\/p>\n
my_dict = {'name': 'Alice', 'age': 25}<\/p>\n
new_entries = {'address': '123 Main St', 'job': 'Engineer'}<\/p>\n
my_dict = my_dict | new_entries<\/p>\n
print(my_dict)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u6211\u4eec\u4f7f\u7528|<\/code>\u64cd\u4f5c\u7b26\u5c06new_entries<\/code>\u4e2d\u7684\u952e\u503c\u5bf9\u6dfb\u52a0\u5230\u4e86my_dict<\/code>\u4e2d\u3002<\/p>\n<\/p>\n
\u516b\u3001\u4f7f\u7528\u8fd0\u7b97\u7b26\u89e3\u5305\uff08Python 3.9+\uff09<\/p>\n
\u5728Python 3.9\u53ca\u66f4\u9ad8\u7248\u672c\u4e2d\uff0c\u5b57\u5178\u7684\u89e3\u5305\u64cd\u4f5c\u4e5f\u53ef\u4ee5\u7528\u4e8e\u6dfb\u52a0\u65b0\u5143\u7d20\u3002<\/p>\n<\/p>\n
my_dict = {'name': 'Alice', 'age': 25}<\/p>\n
new_entries = {'address': '123 Main St', 'job': 'Engineer'}<\/p>\n
my_dict = {<strong>my_dict, <\/strong>new_entries}<\/p>\n
print(my_dict)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u6211\u4eec\u4f7f\u7528<\/code>\u89e3\u5305\u64cd\u4f5c\u7b26\u5c06new_entries<\/code>\u4e2d\u7684\u952e\u503c\u5bf9\u6dfb\u52a0\u5230\u4e86my_dict<\/code>\u4e2d\u3002<\/p>\n<\/p>\n
\u4e5d\u3001\u4f7f\u7528for\u5faa\u73af\u6dfb\u52a0\u591a\u4e2a\u5143\u7d20<\/p>\n
\u4f60\u8fd8\u53ef\u4ee5\u4f7f\u7528for<\/code>\u5faa\u73af\u9010\u4e2a\u6dfb\u52a0\u591a\u4e2a\u5143\u7d20\u5230\u5b57\u5178\u4e2d\u3002<\/p>\n<\/p>\n
my_dict = {'name': 'Alice', 'age': 25}<\/p>\n
new_entries = {'address': '123 Main St', 'job': 'Engineer'}<\/p>\n
for key, value in new_entries.items():<\/p>\n
    my_dict[key] = value<\/p>\n
print(my_dict)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u901a\u8fc7for<\/code>\u5faa\u73af\uff0c\u6211\u4eec\u9010\u4e2a\u5c06new_entries<\/code>\u4e2d\u7684\u952e\u503c\u5bf9\u6dfb\u52a0\u5230\u4e86my_dict<\/code>\u4e2d\u3002<\/p>\n<\/p>\n
\u5341\u3001\u4f7f\u7528\u5b57\u5178\u89e3\u5305\uff08Python 3.5+\uff09<\/p>\n
\u4ecePython 3.5\u5f00\u59cb\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528<\/code>\u89e3\u5305\u64cd\u4f5c\u7b26\u5728\u51fd\u6570\u8c03\u7528\u65f6\u5c06\u5b57\u5178\u89e3\u5305\u4e3a\u5173\u952e\u5b57\u53c2\u6570\uff0c\u4ece\u800c\u6dfb\u52a0\u65b0\u5143\u7d20\u3002<\/p>\n<\/p>\n
def add_entries(entries):<\/p>\n
    return entries<\/p>\n
my_dict = {'name': 'Alice', 'age': 25}<\/p>\n
new_entries = {'address': '123 Main St', 'job': 'Engineer'}<\/p>\n
my_dict = add_entries(<strong>my_dict, <\/strong>new_entries)<\/p>\n
print(my_dict)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u6211\u4eec\u4f7f\u7528<\/code>\u89e3\u5305\u64cd\u4f5c\u7b26\u5c06my_dict<\/code>\u548cnew_entries<\/code>\u4e2d\u7684\u952e\u503c\u5bf9\u89e3\u5305\u4e3a\u5173\u952e\u5b57\u53c2\u6570\uff0c\u5e76\u4f20\u9012\u7ed9\u51fd\u6570add_entries<\/code>\u3002<\/p>\n<\/p>\n
\u901a\u8fc7\u4ee5\u4e0a\u591a\u79cd\u65b9\u6cd5\uff0c\u4f60\u53ef\u4ee5\u7075\u6d3b\u5730\u5728Python\u5b57\u5178\u4e2d\u6dfb\u52a0\u5143\u7d20\u3002\u6839\u636e\u5177\u4f53\u9700\u6c42\u9009\u62e9\u5408\u9002\u7684\u65b9\u6cd5\uff0c\u53ef\u4ee5\u5e2e\u52a9\u4f60\u66f4\u9ad8\u6548\u5730\u64cd\u4f5c\u5b57\u5178\u3002<\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
 \u5982\u4f55\u5728Python\u5b57\u5178\u4e2d\u6dfb\u52a0\u65b0\u7684\u952e\u503c\u5bf9\uff1f<\/strong>
\u5728Python\u5b57\u5178\u4e2d\uff0c\u53ef\u4ee5\u901a\u8fc7\u7b80\u5355\u7684\u8d4b\u503c\u64cd\u4f5c\u6765\u6dfb\u52a0\u65b0\u7684\u952e\u503c\u5bf9\u3002\u53ea\u9700\u4f7f\u7528\u65b0\u7684\u952e\u540d\u5e76\u5c06\u5176\u8d4b\u503c\u4e3a\u76f8\u5e94\u7684\u503c\u3002\u4f8b\u5982\uff0cmy_dict['new_key'] = 'new_value'<\/code>\uff0c\u8fd9\u5c06\u4f1a\u5728\u5b57\u5178\u4e2d\u6dfb\u52a0\u4e00\u4e2a\u952e\u4e3anew_key<\/code>\uff0c\u503c\u4e3anew_value<\/code>\u7684\u5143\u7d20\u3002<\/p>\n
\u53ef\u4ee5\u901a\u8fc7\u54ea\u4e9b\u65b9\u6cd5\u540c\u65f6\u6dfb\u52a0\u591a\u4e2a\u5143\u7d20\u5230\u5b57\u5178\u4e2d\uff1f<\/strong>
\u6709\u591a\u79cd\u65b9\u6cd5\u53ef\u4ee5\u4e00\u6b21\u6027\u6dfb\u52a0\u591a\u4e2a\u952e\u503c\u5bf9\u3002\u4e00\u4e2a\u5e38\u7528\u7684\u65b9\u6cd5\u662f\u4f7f\u7528update()<\/code>\u65b9\u6cd5\uff0c\u4f8b\u5982\uff1amy_dict.update({'key1': 'value1', 'key2': 'value2'})<\/code>\u3002\u6b64\u5916\uff0c\u8fd8\u53ef\u4ee5\u5229\u7528\u5b57\u5178\u63a8\u5bfc\u5f0f\u6216\u5c06\u591a\u4e2a\u952e\u503c\u5bf9\u653e\u5728\u4e00\u4e2a\u5143\u7ec4\u5217\u8868\u4e2d\u8fdb\u884c\u66f4\u65b0\u3002<\/p>\n
\u5982\u679c\u60f3\u8981\u907f\u514d\u91cd\u590d\u7684\u952e\uff0c\u5982\u4f55\u5728\u6dfb\u52a0\u5143\u7d20\u65f6\u8fdb\u884c\u68c0\u67e5\uff1f<\/strong>
\u5728\u6dfb\u52a0\u5143\u7d20\u4e4b\u524d\uff0c\u53ef\u4ee5\u4f7f\u7528in<\/code>\u5173\u952e\u5b57\u68c0\u67e5\u952e\u662f\u5426\u5df2\u5b58\u5728\u4e8e\u5b57\u5178\u4e2d\u3002\u4f8b\u5982\uff0cif 'key' not in my_dict:<\/code>\u53ef\u4ee5\u786e\u4fdd\u53ea\u6709\u5728\u952e\u4e0d\u5b58\u5728\u7684\u60c5\u51b5\u4e0b\u624d\u6dfb\u52a0\u65b0\u5143\u7d20\u3002\u8fd9\u6837\u53ef\u4ee5\u6709\u6548\u907f\u514d\u8986\u76d6\u5df2\u6709\u7684\u503c\uff0c\u786e\u4fdd\u6570\u636e\u7684\u5b8c\u6574\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"\u8981\u5728Python\u5b57\u5178\u4e2d\u52a0\u5165\u5143\u7d20\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528\u76f4\u63a5\u8d4b\u503c\u3001update()\u65b9\u6cd5\u3001fromkeys()\u65b9\u6cd5\u3002\u5176\u4e2d\uff0c\u76f4\u63a5 […]","protected":false},"author":3,"featured_media":1156518,"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\/1156510"}],"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=1156510"}],"version-history":[{"count":"1","href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1156510\/revisions"}],"predecessor-version":[{"id":1156520,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1156510\/revisions\/1156520"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/1156518"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=1156510"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=1156510"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=1156510"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}