{"id":2023,"date":"2024-10-14T14:56:24","date_gmt":"2024-10-14T06:56:24","guid":{"rendered":"http:\/\/blog.xtaa.cn\/?p=2023"},"modified":"2024-10-14T15:58:29","modified_gmt":"2024-10-14T07:58:29","slug":"getattr%e8%af%a6%e8%a7%a3","status":"publish","type":"post","link":"http:\/\/blog.xtaa.cn\/index.php\/2024\/10\/14\/getattr%e8%af%a6%e8%a7%a3\/","title":{"rendered":"getattr\u8be6\u89e3"},"content":{"rendered":"\n

\u4e00\u3001\u57fa\u7840\u7528\u6cd5
getattr() \u662f Python \u5185\u7f6e\u7684\u4e00\u4e2a\u51fd\u6570\uff0c\u53ef\u4ee5\u7528\u6765\u83b7\u53d6\u4e00\u4e2a\u5bf9\u8c61\u7684\u5c5e\u6027\u503c\u6216\u65b9\u6cd5\u3002\u5176\u57fa\u672c\u8bed\u6cd5\u4e3a\uff1a<\/p>\n\n\n\n

getattr(object, name[, default])
1
\u5176\u4e2d\uff0cobject \u662f\u8981\u83b7\u53d6\u5c5e\u6027\u503c\u6216\u65b9\u6cd5\u7684\u5bf9\u8c61\uff1bname \u662f\u8981\u83b7\u53d6\u7684\u5c5e\u6027\u540d\u6216\u65b9\u6cd5\u540d\uff1bdefault \u662f\u53ef\u9009\u53c2\u6570\uff0c\u5f53\u6307\u5b9a\u7684\u5c5e\u6027\u6216\u65b9\u6cd5\u4e0d\u5b58\u5728\u65f6\uff0c\u4f1a\u8fd4\u56de default \u7684\u503c\u3002<\/p>\n\n\n\n

getattr() \u53ef\u4ee5\u901a\u8fc7\u5bf9\u8c61\u5b9e\u4f8b\u6216\u7c7b\u540d\u6765\u83b7\u53d6\u5c5e\u6027\u503c\u6216\u65b9\u6cd5\uff0c\u4e5f\u53ef\u4ee5\u83b7\u53d6\u5185\u7f6e\u51fd\u6570\u3001\u5185\u7f6e\u7c7b\u578b\u548c\u6807\u51c6\u5e93\u4e2d\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\u3002<\/p>\n\n\n\n

\u4e0b\u9762\u662f\u4e00\u4e9b\u5e38\u89c1\u7684\u4f7f\u7528 getattr() \u7684\u6848\u4f8b\uff1a<\/p>\n\n\n\n

\u83b7\u53d6\u5bf9\u8c61\u7684\u5c5e\u6027\u503c
class MyClass:
def init<\/strong>(self):
self.x = 1
self.y = 2<\/p>\n\n\n\n

obj = MyClass()<\/p>\n\n\n\n

print(getattr(obj, ‘x’)) # \u8f93\u51fa 1
print(getattr(obj, ‘y’)) # \u8f93\u51fa 2

\u8fd0\u884c\u8fd0\u884c
\u83b7\u53d6\u5bf9\u8c61\u7684\u65b9\u6cd5
class MyClass:
def my_method(self):
print(‘Hello, world!’)<\/p>\n\n\n\n

obj = MyClass()<\/p>\n\n\n\n

method = getattr(obj, ‘my_method’)
method() # \u8f93\u51fa “Hello, world!”

\u8fd0\u884c\u8fd0\u884c
\u83b7\u53d6\u5185\u7f6e\u51fd\u6570\u548c\u7c7b\u578b
func = getattr(builtins<\/strong>, ‘abs’)
print(func(-1)) # \u8f93\u51fa 1<\/p>\n\n\n\n

type_name = ‘str’
type_obj = getattr(builtins<\/strong>, type_name)
print(type_obj(‘Hello, world!’)) # \u8f93\u51fa “Hello, world!”

\u8fd0\u884c\u8fd0\u884c
\u83b7\u53d6\u6807\u51c6\u5e93\u4e2d\u7684\u5c5e\u6027\u548c\u65b9\u6cd5
import datetime<\/p>\n\n\n\n

now = datetime.datetime.now()<\/p>\n\n\n\n

attr_name = ‘year’
attr_value = getattr(now, attr_name)
print(attr_value) # \u8f93\u51fa\u5f53\u524d\u5e74\u4efd<\/p>\n\n\n\n

method_name = ‘strftime’
method_args = [‘%Y-%m-%d %H:%M:%S’]
method = getattr(now, method_name)
formatted = method(*method_args)
print(formatted) # \u8f93\u51fa\u683c\u5f0f\u5316\u540e\u7684\u65f6\u95f4\u5b57\u7b26\u4e32\uff0c\u5982 “2023-05-06 10:30:00”

\u8fd0\u884c\u8fd0\u884c
\u5728\u5b9e\u9645\u5f00\u53d1\u4e2d\uff0cgetattr() \u8fd8\u53ef\u4ee5\u7528\u4e8e\u5b9e\u73b0\u52a8\u6001\u8c03\u7528\u51fd\u6570\u6216\u65b9\u6cd5\u7684\u529f\u80fd\uff0c\u4ee5\u53ca\u5728\u9700\u8981\u5904\u7406\u5927\u91cf\u7c7b\u4f3c\u5c5e\u6027\u6216\u65b9\u6cd5\u7684\u4ee3\u7801\u65f6\uff0c\u7b80\u5316\u4ee3\u7801\u7684\u7f16\u5199\u3002<\/p>\n\n\n\n

\u4e8c\u3001\u590d\u6742\u6848\u4f8b
getattr() \u8fd8\u53ef\u4ee5\u7ed3\u5408 import_module() \u51fd\u6570\uff0c\u5b9e\u73b0\u52a8\u6001\u6267\u884c\u67d0\u4e2a\u6587\u4ef6\u4e2d\u67d0\u4e2a\u7c7b\u7684\u65b9\u6cd5\u7684\u529f\u80fd\u3002<\/p>\n\n\n\n

\u4e0b\u9762\u662f\u4e00\u4e2a\u7a0d\u5fae\u590d\u6742\u4e00\u4e9b\u7684\u4f8b\u5b50\u3002<\/p>\n\n\n\n

\u5047\u8bbe\u6211\u4eec\u6709\u4e00\u4e2a data.py \u6587\u4ef6\uff0c\u5176\u4e2d\u5b9a\u4e49\u4e86\u4e00\u4e2a Data \u7c7b\u548c\u4e00\u4e9b\u6570\u636e\u64cd\u4f5c\u65b9\u6cd5\uff0c\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n\n\n\n

data.py<\/h1>\n\n\n\n

class Data:
def init<\/strong>(self, data):
self.data = data<\/p>\n\n\n\n

def get(self):\n    return self.data\n\ndef add(self, value):\n    self.data.append(value)\n\ndef remove(self, value):\n    self.data.remove(value)<\/code><\/pre>\n\n\n\n
def load_data():
return [1, 2, 3]<\/p>\n\n\n\n

\u8fd0\u884c\u8fd0\u884c
\u73b0\u5728\u6211\u4eec\u9700\u8981\u5728\u53e6\u4e00\u4e2a\u6a21\u5757\u4e2d\uff0c\u52a8\u6001\u52a0\u8f7d data.py \u6587\u4ef6\uff0c\u5e76\u4f7f\u7528 Data \u7c7b\u7684\u5b9e\u4f8b\u5bf9\u8c61\u8fdb\u884c\u6570\u636e\u64cd\u4f5c\uff0c\u540c\u65f6\u4e5f\u9700\u8981\u4f7f\u7528 load_data() \u51fd\u6570\u8fdb\u884c\u6570\u636e\u7684\u8bfb\u64cd\u4f5c\u3002<\/p>\n\n\n\n
\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n\n\n\n
import importlib<\/p>\n\n\n\n
module_name = ‘data’
class_name = ‘Data’
method_name = ‘get’<\/p>\n\n\n\n
module = importlib.import_module(module_name)
class_obj = getattr(module, class_name)(module.load_data())
method = getattr(class_obj, method_name)
print(method()) # \u8f93\u51fa [1, 2, 3]<\/p>\n\n\n\n
value = 4
method_name = ‘add’
method = getattr(class_obj, method_name)
method(value)<\/p>\n\n\n\n
method_name = ‘get’
method = getattr(class_obj, method_name)
print(method()) # \u8f93\u51fa [1, 2, 3, 4]<\/p>\n\n\n\n
value = 2
method_name = ‘remove’
method = getattr(class_obj, method_name)
method(value)<\/p>\n\n\n\n
method_name = ‘get’
method = getattr(class_obj, method_name)
print(method()) # \u8f93\u51fa [1, 3, 4]<\/p>\n\n\n\n



\u5728\u4e0a\u8ff0\u793a\u4f8b\u4e2d\uff0c\u6211\u4eec\u9996\u5148\u4f7f\u7528 import_module() \u51fd\u6570\u5bfc\u5165\u4e86 data.py \u6587\u4ef6\uff0c\u7136\u540e\u4f7f\u7528 getattr() \u51fd\u6570\u83b7\u53d6\u4e86 Data \u7c7b\u7684\u5bf9\u8c61\u3002\u63a5\u7740\uff0c\u6211\u4eec\u4f7f\u7528 () \u8fd0\u7b97\u7b26\u6267\u884c\u4e86 get()\u3001add() \u548c remove() \u65b9\u6cd5\uff0c\u4ece\u800c\u52a8\u6001\u8fdb\u884c\u4e86\u6570\u636e\u64cd\u4f5c\u3002<\/p>\n\n\n\n
importlib<\/code>\u662fPython\u7684\u4e00\u4e2a\u6807\u51c6\u5e93<\/a>\uff0c\u7528\u4e8e\u5904\u7406\u6a21\u5757\u7684\u5bfc\u5165\u8fc7\u7a0b\u3002\u5b83\u63d0\u4f9b\u4e86\u5bf9Python\u5bfc\u5165\u673a\u5236\u7684\u4f4e\u7ea7\u8bbf\u95ee\uff0c\u5141\u8bb8\u4f60\u5728\u8fd0\u884c\u65f6\u52a8\u6001\u5730\u5bfc\u5165\u548c\u91cd\u8f7d\u6a21\u5757\u3002<\/p>\n\n\n\n
\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u52a8\u6001\u5730\u52a0\u8f7d\u4e86\u4e00\u4e2a Python \u6a21\u5757\uff0c\u5e76\u4f7f\u7528 getattr() \u51fd\u6570\u83b7\u53d6\u4e86\u6a21\u5757\u4e2d\u7684\u7c7b\u548c\u51fd\u6570\u5bf9\u8c61\u3002\u7136\u540e\uff0c\u6211\u4eec\u4f7f\u7528\u8fd9\u4e9b\u5bf9\u8c61\u6765\u52a8\u6001\u5730\u8fdb\u884c\u6570\u636e\u64cd\u4f5c\u3002\u8fd9\u79cd\u52a8\u6001\u52a0\u8f7d\u548c\u6267\u884c\u7684\u65b9\u5f0f\uff0c\u53ef\u4ee5\u4f7f\u4ee3\u7801\u66f4\u52a0\u7075\u6d3b\u548c\u53ef\u6269\u5c55\u3002<\/p>\n\n\n\n
\u4e09\u3001import_module\u4ecb\u7ecd
import_module() \u51fd\u6570\u5f97\u5230\u7684\u662f\u4e00\u4e2a\u6a21\u5757\u5bf9\u8c61\uff0c\u5373\u4e00\u4e2a\u8868\u793a Python \u6a21\u5757\u7684\u5bf9\u8c61\u3002\u6a21\u5757\u5bf9\u8c61\u662f\u4e00\u4e2a\u5305\u542b\u6a21\u5757\u4e2d\u6240\u6709\u5b9a\u4e49\u7684\u7c7b\u3001\u51fd\u6570\u3001\u53d8\u91cf\u7b49\u7684\u547d\u540d\u7a7a\u95f4\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u6a21\u5757\u5bf9\u8c61\u6765\u8bbf\u95ee\u8fd9\u4e9b\u5b9a\u4e49\u3002<\/p>\n\n\n\n
\u4f8b\u5982\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528 module \u5bf9\u8c61\u6765\u8bbf\u95ee data.py \u6587\u4ef6\u4e2d\u5b9a\u4e49\u7684 Data \u7c7b\u548c load_data() \u51fd\u6570\uff0c\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n\n\n\n
import importlib<\/p>\n\n\n\n
module_name = ‘data’<\/p>\n\n\n\n
module = importlib.import_module(module_name)
data = module.Data([1, 2, 3])
loaded_data = module.load_data()
print(loaded_data)<\/p>\n\n\n\n
1
2
3
4
5
6
7
8
9
\u5728\u4e0a\u8ff0\u4ee3\u7801\u4e2d\uff0c\u6211\u4eec\u9996\u5148\u4f7f\u7528 import_module() \u51fd\u6570\u5bfc\u5165\u4e86 data.py \u6587\u4ef6\uff0c\u7136\u540e\u901a\u8fc7 module \u5bf9\u8c61\u8bbf\u95ee\u4e86 Data \u7c7b\u548c load_data() \u51fd\u6570\u3002\u6211\u4eec\u8fd8\u4f7f\u7528 () \u8fd0\u7b97\u7b26\u521b\u5efa\u4e86 Data \u7c7b\u7684\u5b9e\u4f8b\u5bf9\u8c61 data\uff0c\u5e76\u8c03\u7528\u4e86 load_data() \u51fd\u6570\uff0c\u83b7\u53d6\u4e86\u6570\u636e\u5217\u8868 loaded_data\u3002<\/p>\n\n\n\n
\u5173\u4e8e\u52a0\u4e86\u62ec\u53f7\u540e\u76f8\u5f53\u4e8e\u8c03\u7528\u4e86\u76f8\u5e94\u7684\u65b9\u6cd5\uff0c\u8fd9\u662f\u56e0\u4e3a\u5728 Python \u4e2d\uff0c\u51fd\u6570\u548c\u65b9\u6cd5\u90fd\u662f\u53ef\u8c03\u7528\u5bf9\u8c61\u3002\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u4f7f\u7528 () \u8fd0\u7b97\u7b26\u6765\u8c03\u7528\u51fd\u6570\u548c\u65b9\u6cd5\u3002<\/p>\n\n\n\n
\u4f8b\u5982\uff0c\u5728\u4e0a\u8ff0\u4ee3\u7801\u4e2d\uff0c\u6211\u4eec\u4f7f\u7528 () \u8fd0\u7b97\u7b26\u8c03\u7528\u4e86 Data \u7c7b\u7684\u6784\u9020\u51fd\u6570\u548c load_data() \u51fd\u6570\uff0c\u4ece\u800c\u521b\u5efa\u4e86 data \u5bf9\u8c61\u548c\u83b7\u53d6\u4e86 loaded_data \u6570\u636e\u3002\u8fd9\u4e0e\u76f4\u63a5\u8c03\u7528\u7c7b\u6216\u51fd\u6570\u7684\u65b9\u5f0f\u662f\u76f8\u540c\u7684\uff0c\u4f8b\u5982\uff1a<\/p>\n\n\n\n
data = Data([1, 2, 3])
loaded_data = load_data()
print(loaded_data)
1
2
3
\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u6211\u4eec\u76f4\u63a5\u8c03\u7528\u4e86\u7c7b\u548c\u51fd\u6570\uff0c\u5e76\u901a\u8fc7\u5b83\u4eec\u6765\u521b\u5efa\u4e86\u5bf9\u8c61\u548c\u83b7\u53d6\u4e86\u6570\u636e\uff0c\u800c\u4e0d\u9700\u8981\u4f7f\u7528\u6a21\u5757\u5bf9\u8c61\u6765\u8bbf\u95ee\u5b83\u4eec\u3002
<\/p>\n\n\n\n
\u539f\u6587\u94fe\u63a5\uff1ahttps:\/\/blog.csdn.net\/mall_lucy\/article\/details\/130531793<\/p>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
\u4e00\u3001\u57fa\u7840\u7528\u6cd5getattr() \u662f Python \u5185\u7f6e\u7684\u4e00\u4e2a\u51fd\u6570\uff0c\u53ef\u4ee5\u7528\u6765\u83b7\u53d6\u4e00\u4e2a\u5bf9\u8c61\u7684\u5c5e\u6027\u503c\u6216\u65b9\u6cd5\u3002\u5176\u57fa\u672c\u8bed […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[],"class_list":["post-2023","post","type-post","status-publish","format-standard","hentry","category-10"],"_links":{"self":[{"href":"http:\/\/blog.xtaa.cn\/index.php\/wp-json\/wp\/v2\/posts\/2023","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/blog.xtaa.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/blog.xtaa.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/blog.xtaa.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/blog.xtaa.cn\/index.php\/wp-json\/wp\/v2\/comments?post=2023"}],"version-history":[{"count":4,"href":"http:\/\/blog.xtaa.cn\/index.php\/wp-json\/wp\/v2\/posts\/2023\/revisions"}],"predecessor-version":[{"id":2027,"href":"http:\/\/blog.xtaa.cn\/index.php\/wp-json\/wp\/v2\/posts\/2023\/revisions\/2027"}],"wp:attachment":[{"href":"http:\/\/blog.xtaa.cn\/index.php\/wp-json\/wp\/v2\/media?parent=2023"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/blog.xtaa.cn\/index.php\/wp-json\/wp\/v2\/categories?post=2023"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/blog.xtaa.cn\/index.php\/wp-json\/wp\/v2\/tags?post=2023"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}