{"id":1105251,"date":"2025-01-08T16:29:12","date_gmt":"2025-01-08T08:29:12","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/1105251.html"},"modified":"2025-01-08T16:29:14","modified_gmt":"2025-01-08T08:29:14","slug":"python%e5%bd%93%e4%b8%ad%e5%a6%82%e4%bd%95%e5%8f%96%e5%87%ba%e5%ad%97%e5%85%b8%e9%87%8c%e9%9d%a2%e7%9a%84%e5%80%bc","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/1105251.html","title":{"rendered":"python\u5f53\u4e2d\u5982\u4f55\u53d6\u51fa\u5b57\u5178\u91cc\u9762\u7684\u503c"},"content":{"rendered":"

\"python\u5f53\u4e2d\u5982\u4f55\u53d6\u51fa\u5b57\u5178\u91cc\u9762\u7684\u503c\"<\/p>\n

\u5728Python\u4e2d\uff0c\u53ef\u4ee5\u901a\u8fc7\u591a\u79cd\u65b9\u6cd5\u6765\u53d6\u51fa\u5b57\u5178\u4e2d\u7684\u503c\uff0c\u5982\u901a\u8fc7\u952e\u8bbf\u95ee\u3001\u4f7f\u7528get()\u65b9\u6cd5\u3001\u4f7f\u7528items()\u65b9\u6cd5\u3001\u4f7f\u7528values()\u65b9\u6cd5\u7b49\u3002<\/strong> \u5176\u4e2d\uff0c\u6700\u5e38\u7528\u7684\u65b9\u6cd5\u662f\u901a\u8fc7\u952e\u76f4\u63a5\u8bbf\u95ee\u548c\u4f7f\u7528get()\u65b9\u6cd5\u3002\u901a\u8fc7\u952e\u76f4\u63a5\u8bbf\u95ee\u662f\u4e00\u79cd\u76f4\u63a5\u4e14\u9ad8\u6548\u7684\u65b9\u6cd5\uff0c\u800c\u4f7f\u7528get()\u65b9\u6cd5\u5219\u53ef\u4ee5\u5728\u952e\u4e0d\u5b58\u5728\u65f6\u8fd4\u56de\u4e00\u4e2a\u9ed8\u8ba4\u503c\uff0c\u4ece\u800c\u907f\u514d\u7a0b\u5e8f\u51fa\u9519\u3002<\/p>\n<\/p>\n

\u901a\u8fc7\u952e\u8bbf\u95ee\u5b57\u5178\u4e2d\u7684\u503c\u662f\u6700\u5e38\u89c1\u7684\u65b9\u6cd5\u3002\u5b57\u5178\u7684\u952e\u662f\u552f\u4e00\u7684\uff0c\u53ef\u4ee5\u901a\u8fc7\u6307\u5b9a\u952e\u6765\u83b7\u53d6\u5bf9\u5e94\u7684\u503c\u3002\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u5047\u8bbe\u6709\u4e00\u4e2a\u5b57\u5178student<\/code>\u5305\u542b\u5b66\u751f\u7684\u4fe1\u606f\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u952e\u6765\u83b7\u53d6\u5b66\u751f\u7684\u59d3\u540d\u3002<\/p>\n<\/p>\n

student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
name = student['name']<\/p>\n
print(name)  # \u8f93\u51fa\uff1aJohn<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u8fd9\u4e2a\u793a\u4f8b\u4e2d\uff0c\u901a\u8fc7\u952e'name'\u8bbf\u95ee\u5b57\u5178student<\/code>\u4e2d\u7684\u503c\uff0c\u6210\u529f\u83b7\u53d6\u5b66\u751f\u7684\u59d3\u540d'John'\u3002<\/p>\n<\/p>\n
\u4e00\u3001\u901a\u8fc7\u952e\u8bbf\u95ee\u5b57\u5178\u4e2d\u7684\u503c<\/h3>\n<\/p>\n
\u901a\u8fc7\u952e\u8bbf\u95ee\u662f\u6700\u57fa\u672c\u7684\u65b9\u6cd5\u3002\u5b57\u5178\u4e2d\u7684\u952e\u662f\u552f\u4e00\u7684\uff0c\u53ef\u4ee5\u901a\u8fc7\u952e\u6765\u83b7\u53d6\u5bf9\u5e94\u7684\u503c\u3002\u4f7f\u7528\u8fd9\u79cd\u65b9\u6cd5\u65f6\uff0c\u5982\u679c\u8bbf\u95ee\u7684\u952e\u4e0d\u5b58\u5728\uff0c\u4f1a\u629b\u51faKeyError<\/code>\u5f02\u5e38\u3002<\/p>\n<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
name = student['name']<\/p>\n
print(name)  # \u8f93\u51fa\uff1aJohn<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u7684\u4f18\u70b9\u662f\u76f4\u63a5\u3001\u9ad8\u6548\uff0c\u4f46\u9700\u8981\u786e\u4fdd\u8bbf\u95ee\u7684\u952e\u5b58\u5728\uff0c\u5426\u5219\u4f1a\u629b\u51fa\u5f02\u5e38\u3002<\/strong> <\/p>\n<\/p>\n
\u4e8c\u3001\u4f7f\u7528get()\u65b9\u6cd5<\/h3>\n<\/p>\n
get()<\/code>\u65b9\u6cd5\u7528\u4e8e\u8bbf\u95ee\u5b57\u5178\u4e2d\u7684\u503c\uff0c\u5f53\u952e\u4e0d\u5b58\u5728\u65f6\uff0c\u53ef\u4ee5\u8fd4\u56de\u4e00\u4e2a\u9ed8\u8ba4\u503c\uff0c\u4ece\u800c\u907f\u514d\u7a0b\u5e8f\u629b\u51faKeyError<\/code>\u5f02\u5e38\u3002<\/p>\n<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
name = student.get('name', 'Unknown')<\/p>\n
print(name)  # \u8f93\u51fa\uff1aJohn<\/p>\n
height = student.get('height', 'Unknown')<\/p>\n
print(height)  # \u8f93\u51fa\uff1aUnknown<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4f7f\u7528get()\u65b9\u6cd5\u53ef\u4ee5\u63d0\u4f9b\u4e00\u4e2a\u9ed8\u8ba4\u503c\uff0c\u5f53\u952e\u4e0d\u5b58\u5728\u65f6\u8fd4\u56de\u8be5\u9ed8\u8ba4\u503c\uff0c\u4ece\u800c\u63d0\u9ad8\u4ee3\u7801\u7684\u5065\u58ee\u6027\u3002<\/strong><\/p>\n<\/p>\n
\u4e09\u3001\u4f7f\u7528items()\u65b9\u6cd5<\/h3>\n<\/p>\n
items()<\/code>\u65b9\u6cd5\u8fd4\u56de\u4e00\u4e2a\u5305\u542b\u5b57\u5178\u4e2d\u6240\u6709\u952e\u503c\u5bf9\u7684\u89c6\u56fe\u5bf9\u8c61\uff0c\u53ef\u4ee5\u901a\u8fc7\u904d\u5386\u8fd9\u4e2a\u5bf9\u8c61\u6765\u83b7\u53d6\u6240\u6709\u952e\u503c\u5bf9\u3002<\/p>\n<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
for key, value in student.items():<\/p>\n
    print(f"{key}: {value}")<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u904d\u5386\u5b57\u5178\u4e2d\u6240\u6709\u952e\u503c\u5bf9\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u56db\u3001\u4f7f\u7528values()\u65b9\u6cd5<\/h3>\n<\/p>\n
values()<\/code>\u65b9\u6cd5\u8fd4\u56de\u4e00\u4e2a\u5305\u542b\u5b57\u5178\u4e2d\u6240\u6709\u503c\u7684\u89c6\u56fe\u5bf9\u8c61\uff0c\u53ef\u4ee5\u901a\u8fc7\u904d\u5386\u8fd9\u4e2a\u5bf9\u8c61\u6765\u83b7\u53d6\u6240\u6709\u503c\u3002<\/p>\n<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
for value in student.values():<\/p>\n
    print(value)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u53ea\u9700\u8981\u83b7\u53d6\u5b57\u5178\u4e2d\u6240\u6709\u503c\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u4e94\u3001\u4f7f\u7528keys()\u65b9\u6cd5<\/h3>\n<\/p>\n
keys()<\/code>\u65b9\u6cd5\u8fd4\u56de\u4e00\u4e2a\u5305\u542b\u5b57\u5178\u4e2d\u6240\u6709\u952e\u7684\u89c6\u56fe\u5bf9\u8c61\uff0c\u53ef\u4ee5\u901a\u8fc7\u904d\u5386\u8fd9\u4e2a\u5bf9\u8c61\u6765\u83b7\u53d6\u6240\u6709\u952e\u3002<\/p>\n<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
for key in student.keys():<\/p>\n
    print(key)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u53ea\u9700\u8981\u83b7\u53d6\u5b57\u5178\u4e2d\u6240\u6709\u952e\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u516d\u3001\u4f7f\u7528\u5b57\u5178\u7684pop()\u65b9\u6cd5<\/h3>\n<\/p>\n
pop()<\/code>\u65b9\u6cd5\u7528\u4e8e\u5220\u9664\u5b57\u5178\u4e2d\u7684\u6307\u5b9a\u952e\u503c\u5bf9\uff0c\u5e76\u8fd4\u56de\u8be5\u952e\u5bf9\u5e94\u7684\u503c\u3002\u5982\u679c\u952e\u4e0d\u5b58\u5728\uff0c\u53ef\u4ee5\u8fd4\u56de\u4e00\u4e2a\u9ed8\u8ba4\u503c\u3002<\/p>\n<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
age = student.pop('age', 'Unknown')<\/p>\n
print(age)  # \u8f93\u51fa\uff1a22<\/p>\n
height = student.pop('height', 'Unknown')<\/p>\n
print(height)  # \u8f93\u51fa\uff1aUnknown<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u4e0d\u4ec5\u53ef\u4ee5\u83b7\u53d6\u503c\uff0c\u8fd8\u4f1a\u4ece\u5b57\u5178\u4e2d\u5220\u9664\u8be5\u952e\u503c\u5bf9\u3002<\/strong><\/p>\n<\/p>\n
\u4e03\u3001\u4f7f\u7528\u5b57\u5178\u7684popitem()\u65b9\u6cd5<\/h3>\n<\/p>\n
popitem()<\/code>\u65b9\u6cd5\u7528\u4e8e\u5220\u9664\u5e76\u8fd4\u56de\u5b57\u5178\u4e2d\u7684\u6700\u540e\u4e00\u4e2a\u952e\u503c\u5bf9\u3002\u8be5\u65b9\u6cd5\u5728Python 3.7\u53ca\u4ee5\u540e\u7248\u672c\u4e2d\u6309\u7167\u63d2\u5165\u987a\u5e8f\u5de5\u4f5c\u3002<\/p>\n<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
last_item = student.popitem()<\/p>\n
print(last_item)  # \u8f93\u51fa\uff1a('major', 'Computer Science')<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u5220\u9664\u5e76\u83b7\u53d6\u5b57\u5178\u4e2d\u6700\u540e\u4e00\u4e2a\u952e\u503c\u5bf9\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u516b\u3001\u4f7f\u7528\u5b57\u5178\u7684setdefault()\u65b9\u6cd5<\/h3>\n<\/p>\n
setdefault()<\/code>\u65b9\u6cd5\u7528\u4e8e\u83b7\u53d6\u5b57\u5178\u4e2d\u6307\u5b9a\u952e\u7684\u503c\uff0c\u5982\u679c\u952e\u4e0d\u5b58\u5728\uff0c\u5219\u5411\u5b57\u5178\u4e2d\u6dfb\u52a0\u8be5\u952e\uff0c\u5e76\u5c06\u5176\u503c\u8bbe\u4e3a\u9ed8\u8ba4\u503c\u3002<\/p>\n<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
name = student.setdefault('name', 'Unknown')<\/p>\n
print(name)  # \u8f93\u51fa\uff1aJohn<\/p>\n
height = student.setdefault('height', 175)<\/p>\n
print(height)  # \u8f93\u51fa\uff1a175<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u4e0d\u4ec5\u53ef\u4ee5\u83b7\u53d6\u503c\uff0c\u8fd8\u53ef\u4ee5\u5728\u952e\u4e0d\u5b58\u5728\u65f6\u6dfb\u52a0\u65b0\u7684\u952e\u503c\u5bf9\u3002<\/strong><\/p>\n<\/p>\n
\u4e5d\u3001\u901a\u8fc7\u5b57\u5178\u63a8\u5bfc\u5f0f\u83b7\u53d6\u503c<\/h3>\n<\/p>\n
\u5b57\u5178\u63a8\u5bfc\u5f0f\u662f\u4e00\u79cd\u7b80\u6d01\u7684\u65b9\u5f0f\uff0c\u53ef\u4ee5\u6839\u636e\u67d0\u4e9b\u6761\u4ef6\u83b7\u53d6\u5b57\u5178\u4e2d\u7684\u503c\u3002<\/p>\n<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
\u83b7\u53d6\u6240\u6709\u503c\u5927\u4e8e20\u7684\u952e\u503c\u5bf9<\/strong><\/h2>\n
filtered_dict = {k: v for k, v in student.items() if isinstance(v, int) and v > 20}<\/p>\n
print(filtered_dict)  # \u8f93\u51fa\uff1a{'age': 22}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u6839\u636e\u67d0\u4e9b\u6761\u4ef6\u83b7\u53d6\u5b57\u5178\u4e2d\u503c\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u5341\u3001\u901a\u8fc7\u5b57\u5178\u7684update()\u65b9\u6cd5<\/h3>\n<\/p>\n
update()<\/code>\u65b9\u6cd5\u7528\u4e8e\u66f4\u65b0\u5b57\u5178\u4e2d\u7684\u503c\uff0c\u5982\u679c\u952e\u4e0d\u5b58\u5728\uff0c\u5219\u6dfb\u52a0\u65b0\u7684\u952e\u503c\u5bf9\u3002<\/p>\n<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
update_info = {'age': 23, 'height': 175}<\/p>\n
student.update(update_info)<\/p>\n
print(student)  # \u8f93\u51fa\uff1a{'name': 'John', 'age': 23, 'major': 'Computer Science', 'height': 175}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u6279\u91cf\u66f4\u65b0\u6216\u6dfb\u52a0\u5b57\u5178\u4e2d\u7684\u952e\u503c\u5bf9\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u5341\u4e00\u3001\u901a\u8fc7\u5b57\u5178\u7684fromkeys()\u65b9\u6cd5<\/h3>\n<\/p>\n
fromkeys()<\/code>\u65b9\u6cd5\u7528\u4e8e\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5b57\u5178\uff0c\u4f7f\u7528\u6307\u5b9a\u7684\u952e\u548c\u9ed8\u8ba4\u503c\u3002\u53ef\u4ee5\u901a\u8fc7\u904d\u5386\u65b0\u5b57\u5178\u83b7\u53d6\u503c\u3002<\/p>\n<\/p>\n
keys = ['name', 'age', 'major']<\/p>\n
default_value = 'Unknown'<\/p>\n
new_dict = dict.fromkeys(keys, default_value)<\/p>\n
print(new_dict)  # \u8f93\u51fa\uff1a{'name': 'Unknown', 'age': 'Unknown', 'major': 'Unknown'}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u521b\u5efa\u5e76\u521d\u59cb\u5316\u4e00\u4e2a\u65b0\u7684\u5b57\u5178\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u5341\u4e8c\u3001\u901a\u8fc7\u5b57\u5178\u7684copy()\u65b9\u6cd5<\/h3>\n<\/p>\n
copy()<\/code>\u65b9\u6cd5\u7528\u4e8e\u521b\u5efa\u5b57\u5178\u7684\u6d45\u62f7\u8d1d\uff0c\u53ef\u4ee5\u901a\u8fc7\u904d\u5386\u62f7\u8d1d\u5b57\u5178\u83b7\u53d6\u503c\u3002<\/p>\n<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
student_copy = student.copy()<\/p>\n
print(student_copy)  # \u8f93\u51fa\uff1a{'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u521b\u5efa\u5b57\u5178\u7684\u526f\u672c\u5e76\u5bf9\u5176\u8fdb\u884c\u64cd\u4f5c\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u5341\u4e09\u3001\u901a\u8fc7\u5b57\u5178\u7684clear()\u65b9\u6cd5<\/h3>\n<\/p>\n
clear()<\/code>\u65b9\u6cd5\u7528\u4e8e\u6e05\u7a7a\u5b57\u5178\u4e2d\u7684\u6240\u6709\u952e\u503c\u5bf9\uff0c\u53ef\u4ee5\u5728\u6e05\u7a7a\u4e4b\u524d\u83b7\u53d6\u6240\u6709\u503c\u3002<\/p>\n<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
all_values = list(student.values())<\/p>\n
student.clear()<\/p>\n
print(all_values)  # \u8f93\u51fa\uff1a['John', 22, 'Computer Science']<\/p>\n
print(student)  # \u8f93\u51fa\uff1a{}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u5728\u6e05\u7a7a\u5b57\u5178\u4e4b\u524d\u83b7\u53d6\u6240\u6709\u503c\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u5341\u56db\u3001\u901a\u8fc7\u5b57\u5178\u7684update()\u65b9\u6cd5\u5408\u5e76\u5b57\u5178<\/h3>\n<\/p>\n
update()<\/code>\u65b9\u6cd5\u53ef\u4ee5\u7528\u4e8e\u5c06\u4e00\u4e2a\u5b57\u5178\u7684\u952e\u503c\u5bf9\u5408\u5e76\u5230\u53e6\u4e00\u4e2a\u5b57\u5178\u4e2d\uff0c\u4ece\u800c\u83b7\u53d6\u5408\u5e76\u540e\u7684\u5b57\u5178\u503c\u3002<\/p>\n<\/p>\n
student = {'name': 'John', 'age': 22}<\/p>\n
additional_info = {'major': 'Computer Science', 'height': 175}<\/p>\n
student.update(additional_info)<\/p>\n
print(student)  # \u8f93\u51fa\uff1a{'name': 'John', 'age': 22, 'major': 'Computer Science', 'height': 175}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u5408\u5e76\u4e24\u4e2a\u5b57\u5178\u7684\u952e\u503c\u5bf9\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u5341\u4e94\u3001\u901a\u8fc7\u5217\u8868\u63a8\u5bfc\u5f0f\u83b7\u53d6\u5d4c\u5957\u5b57\u5178\u7684\u503c<\/h3>\n<\/p>\n
\u5728\u5904\u7406\u5d4c\u5957\u5b57\u5178\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528\u5217\u8868\u63a8\u5bfc\u5f0f\u6765\u83b7\u53d6\u5d4c\u5957\u5b57\u5178\u4e2d\u7684\u503c\u3002<\/p>\n<\/p>\n
students = [{'name': 'John', 'age': 22}, {'name': 'Jane', 'age': 21}]<\/p>\n
names = [student['name'] for student in students]<\/p>\n
print(names)  # \u8f93\u51fa\uff1a['John', 'Jane']<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u4ece\u5d4c\u5957\u5b57\u5178\u4e2d\u63d0\u53d6\u7279\u5b9a\u503c\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u5341\u516d\u3001\u901a\u8fc7\u51fd\u6570\u9012\u5f52\u83b7\u53d6\u5d4c\u5957\u5b57\u5178\u7684\u503c<\/h3>\n<\/p>\n
\u9012\u5f52\u51fd\u6570\u662f\u4e00\u79cd\u5f3a\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u7528\u4e8e\u5904\u7406\u5d4c\u5957\u5b57\u5178\u7ed3\u6784\uff0c\u4ece\u800c\u83b7\u53d6\u5d4c\u5957\u5b57\u5178\u4e2d\u7684\u503c\u3002<\/p>\n<\/p>\n
def get_nested_value(d, keys):<\/p>\n
    if not keys:<\/p>\n
        return d<\/p>\n
    return get_nested_value(d[keys[0]], keys[1:])<\/p>\n
nested_dict = {'student': {'name': 'John', 'detAI<\/a>ls': {'age': 22, 'major': 'Computer Science'}}}<\/p>\n
keys = ['student', 'details', 'age']<\/p>\n
age = get_nested_value(nested_dict, keys)<\/p>\n
print(age)  # \u8f93\u51fa\uff1a22<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u5904\u7406\u590d\u6742\u7684\u5d4c\u5957\u5b57\u5178\u7ed3\u6784\uff0c\u5e76\u53ef\u4ee5\u901a\u8fc7\u9012\u5f52\u83b7\u53d6\u5d4c\u5957\u5b57\u5178\u4e2d\u7684\u503c\u3002<\/strong><\/p>\n<\/p>\n
\u5341\u4e03\u3001\u901a\u8fc7json\u6a21\u5757\u5904\u7406\u5b57\u5178<\/h3>\n<\/p>\n
\u5728\u5904\u7406\u590d\u6742\u7684\u6570\u636e\u7ed3\u6784\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528json<\/code>\u6a21\u5757\u5c06\u5b57\u5178\u8f6c\u6362\u4e3aJSON\u5b57\u7b26\u4e32\uff0c\u7136\u540e\u89e3\u6790JSON\u5b57\u7b26\u4e32\u83b7\u53d6\u503c\u3002<\/p>\n<\/p>\n
import json<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
student_json = json.dumps(student)<\/p>\n
student_dict = json.loads(student_json)<\/p>\n
name = student_dict['name']<\/p>\n
print(name)  # \u8f93\u51fa\uff1aJohn<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u5c06\u5b57\u5178\u4e0e\u5176\u4ed6\u7cfb\u7edf\u8fdb\u884c\u6570\u636e\u4ea4\u6362\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u5341\u516b\u3001\u901a\u8fc7pandas\u6a21\u5757\u5904\u7406\u5b57\u5178<\/h3>\n<\/p>\n
\u5728\u6570\u636e\u5206\u6790\u548c\u5904\u7406\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528pandas<\/code>\u6a21\u5757\u5c06\u5b57\u5178\u8f6c\u6362\u4e3aDataFrame\uff0c\u4ece\u800c\u65b9\u4fbf\u5730\u83b7\u53d6\u503c\u3002<\/p>\n<\/p>\n
import pandas as pd<\/p>\n
student = {'name': 'John', 'age': 22, 'major': 'Computer Science'}<\/p>\n
df = pd.DataFrame([student])<\/p>\n
name = df.loc[0, 'name']<\/p>\n
print(name)  # \u8f93\u51fa\uff1aJohn<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u8fdb\u884c\u6570\u636e\u5206\u6790\u548c\u5904\u7406\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u5341\u4e5d\u3001\u901a\u8fc7collections\u6a21\u5757\u7684defaultdict\u5904\u7406\u5b57\u5178<\/h3>\n<\/p>\n
collections<\/code>\u6a21\u5757\u7684defaultdict<\/code>\u7c7b\u63d0\u4f9b\u4e86\u4e00\u79cd\u5904\u7406\u5b57\u5178\u9ed8\u8ba4\u503c\u7684\u4fbf\u6377\u65b9\u5f0f\uff0c\u53ef\u4ee5\u7528\u4e8e\u83b7\u53d6\u548c\u5904\u7406\u5b57\u5178\u4e2d\u7684\u503c\u3002<\/p>\n<\/p>\n
from collections import defaultdict<\/p>\n
student = defaultdict(lambda: 'Unknown', {'name': 'John', 'age': 22, 'major': 'Computer Science'})<\/p>\n
name = student['name']<\/p>\n
height = student['height']<\/p>\n
print(name)  # \u8f93\u51fa\uff1aJohn<\/p>\n
print(height)  # \u8f93\u51fa\uff1aUnknown<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u5904\u7406\u9ed8\u8ba4\u503c\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u4e8c\u5341\u3001\u901a\u8fc7collections\u6a21\u5757\u7684OrderedDict\u5904\u7406\u5b57\u5178<\/h3>\n<\/p>\n
collections<\/code>\u6a21\u5757\u7684OrderedDict<\/code>\u7c7b\u63d0\u4f9b\u4e86\u4e00\u79cd\u6709\u5e8f\u5b57\u5178\uff0c\u53ef\u4ee5\u6309\u63d2\u5165\u987a\u5e8f\u83b7\u53d6\u5b57\u5178\u4e2d\u7684\u503c\u3002<\/p>\n<\/p>\n
from collections import OrderedDict<\/p>\n
student = OrderedDict([('name', 'John'), ('age', 22), ('major', 'Computer Science')])<\/p>\n
for key, value in student.items():<\/p>\n
    print(f"{key}: {value}")<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u4fdd\u6301\u5b57\u5178\u952e\u503c\u5bf9\u63d2\u5165\u987a\u5e8f\u7684\u60c5\u51b5\u3002<\/strong><\/p>\n<\/p>\n
\u603b\u7ed3\u8d77\u6765\uff0cPython\u63d0\u4f9b\u4e86\u591a\u79cd\u65b9\u6cd5\u6765\u83b7\u53d6\u5b57\u5178\u4e2d\u7684\u503c\uff0c\u5305\u62ec\u901a\u8fc7\u952e\u8bbf\u95ee\u3001\u4f7f\u7528get()\u65b9\u6cd5\u3001\u4f7f\u7528items()\u65b9\u6cd5\u3001\u4f7f\u7528values()\u65b9\u6cd5\u3001\u4f7f\u7528keys()\u65b9\u6cd5\u3001\u4f7f\u7528pop()\u65b9\u6cd5\u3001\u4f7f\u7528popitem()\u65b9\u6cd5\u3001\u4f7f\u7528setdefault()\u65b9\u6cd5\u3001\u901a\u8fc7\u5b57\u5178\u63a8\u5bfc\u5f0f\u83b7\u53d6\u503c\u3001\u901a\u8fc7\u5b57\u5178\u7684update()\u65b9\u6cd5\u3001\u901a\u8fc7\u5b57\u5178\u7684fromkeys()\u65b9\u6cd5\u3001\u901a\u8fc7\u5b57\u5178\u7684copy()\u65b9\u6cd5\u3001\u901a\u8fc7\u5b57\u5178\u7684clear()\u65b9\u6cd5\u3001\u901a\u8fc7\u5217\u8868\u63a8\u5bfc\u5f0f\u83b7\u53d6\u5d4c\u5957\u5b57\u5178\u7684\u503c\u3001\u901a\u8fc7\u51fd\u6570\u9012\u5f52\u83b7\u53d6\u5d4c\u5957\u5b57\u5178\u7684\u503c\u3001\u901a\u8fc7json\u6a21\u5757\u5904\u7406\u5b57\u5178\u3001\u901a\u8fc7pandas\u6a21\u5757\u5904\u7406\u5b57\u5178\u3001\u901a\u8fc7collections\u6a21\u5757\u7684defaultdict\u5904\u7406\u5b57\u5178\u3001\u901a\u8fc7collections\u6a21\u5757\u7684OrderedDict\u5904\u7406\u5b57\u5178\u7b49\u3002\u9009\u62e9\u5408\u9002\u7684\u65b9\u6cd5\u53ef\u4ee5\u6839\u636e\u5177\u4f53\u7684\u4f7f\u7528\u573a\u666f\u548c\u9700\u6c42\u6765\u51b3\u5b9a\uff0c\u4ece\u800c\u6709\u6548\u5730\u83b7\u53d6\u548c\u5904\u7406\u5b57\u5178\u4e2d\u7684\u503c\u3002<\/strong><\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
 \u5728Python\u4e2d\uff0c\u5982\u4f55\u8bbf\u95ee\u5b57\u5178\u7684\u503c\uff1f<\/strong>
\u8bbf\u95ee\u5b57\u5178\u7684\u503c\u53ef\u4ee5\u901a\u8fc7\u952e\u6765\u5b9e\u73b0\u3002\u4f7f\u7528\u65b9\u62ec\u53f7[]<\/code>\u6216get()<\/code>\u65b9\u6cd5\u90fd\u53ef\u4ee5\u3002\u6bd4\u5982\uff0c\u5047\u8bbe\u6709\u4e00\u4e2a\u5b57\u5178my_dict = {'name': 'Alice', 'age': 25}<\/code>\uff0c\u8981\u83b7\u53d6name<\/code>\u7684\u503c\uff0c\u53ef\u4ee5\u4f7f\u7528my_dict['name']<\/code>\u6216my_dict.get('name')<\/code>\u3002\u4e24\u8005\u90fd\u5c06\u8fd4\u56de'Alice'<\/code>\u3002<\/p>\n
\u5982\u679c\u5c1d\u8bd5\u83b7\u53d6\u4e00\u4e2a\u4e0d\u5b58\u5728\u7684\u952e\u7684\u503c\uff0c\u4f1a\u53d1\u751f\u4ec0\u4e48\uff1f<\/strong>
\u5982\u679c\u4f7f\u7528\u65b9\u62ec\u53f7\u8bbf\u95ee\u4e00\u4e2a\u4e0d\u5b58\u5728\u7684\u952e\uff0c\u4f1a\u5f15\u53d1KeyError<\/code>\u5f02\u5e38\u3002\u4e3a\u4e86\u907f\u514d\u8fd9\u79cd\u60c5\u51b5\uff0c\u53ef\u4ee5\u4f7f\u7528get()<\/code>\u65b9\u6cd5\uff0c\u8be5\u65b9\u6cd5\u5728\u952e\u4e0d\u5b58\u5728\u65f6\u8fd4\u56deNone<\/code>\u6216\u81ea\u5b9a\u4e49\u7684\u9ed8\u8ba4\u503c\u3002\u4f8b\u5982\uff0cmy_dict.get('address', 'Not Found')<\/code>\u5c06\u8fd4\u56de'Not Found'<\/code>\uff0c\u5982\u679c'address'<\/code>\u952e\u5728\u5b57\u5178\u4e2d\u4e0d\u5b58\u5728\u3002<\/p>\n
\u5982\u4f55\u904d\u5386\u5b57\u5178\u5e76\u63d0\u53d6\u6240\u6709\u503c\uff1f<\/strong>
\u53ef\u4ee5\u4f7f\u7528values()<\/code>\u65b9\u6cd5\u6765\u63d0\u53d6\u5b57\u5178\u4e2d\u7684\u6240\u6709\u503c\u3002\u5bf9\u4e8e\u5b57\u5178my_dict<\/code>\uff0c\u53ef\u4ee5\u901a\u8fc7my_dict.values()<\/code>\u6765\u83b7\u53d6\u4e00\u4e2a\u5305\u542b\u6240\u6709\u503c\u7684\u89c6\u56fe\u5bf9\u8c61\u3002\u5982\u679c\u9700\u8981\u5c06\u8fd9\u4e9b\u503c\u8f6c\u6362\u4e3a\u5217\u8868\uff0c\u53ef\u4ee5\u4f7f\u7528list(my_dict.values())<\/code>\uff0c\u8fd9\u6837\u5c31\u80fd\u5f97\u5230\u4e00\u4e2a\u5217\u8868\u5f62\u5f0f\u7684\u6240\u6709\u503c\uff0c\u4f8b\u5982['Alice', 25]<\/code>\u3002\u8fd9\u79cd\u65b9\u6cd5\u975e\u5e38\u9002\u5408\u9700\u8981\u5bf9\u5b57\u5178\u4e2d\u6240\u6709\u503c\u8fdb\u884c\u64cd\u4f5c\u7684\u573a\u666f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"\u5728Python\u4e2d\uff0c\u53ef\u4ee5\u901a\u8fc7\u591a\u79cd\u65b9\u6cd5\u6765\u53d6\u51fa\u5b57\u5178\u4e2d\u7684\u503c\uff0c\u5982\u901a\u8fc7\u952e\u8bbf\u95ee\u3001\u4f7f\u7528get()\u65b9\u6cd5\u3001\u4f7f\u7528items()\u65b9\u6cd5\u3001 […]","protected":false},"author":3,"featured_media":1105259,"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\/1105251"}],"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=1105251"}],"version-history":[{"count":"1","href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1105251\/revisions"}],"predecessor-version":[{"id":1105261,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1105251\/revisions\/1105261"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/1105259"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=1105251"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=1105251"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=1105251"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}