本文實例總結了python動態加載包的方法。分享給大家供大家參考，具體如下：
動態加載模塊有三種方法
1. 使用系統函數__import_()
stringmodule = __import__('string') 2. 使用imp 模塊
import imp stringmodule = imp.load_module('string',*imp.find_module('string'))imp.load_source("TYACMgrHandler_"+app.upper(), filepath) 3. 用exec
import_string = "import string as stringmodule"exec import_string
變量是否存在
1. hasattr(Test,'t')
2. 'var' in locals().keys()
3. 'var' in dir()
4. vars().has_key('s')
動態增加屬性
class Obj(object): passdef main(): list=["a","b", "c"] for i inrange(1,len(list),2): Obj = type('Obj',(),{list[i]:lambdaself,s:obj.__setattr__(s.split(" = ")[0],s.split(" = ")[1])}) obj =Obj() for i inrange(0,len(list),2): obj.__setattr__(list[i],list[i]) obj.a =1 obj.b("a =2") obj.b("c =3") printobj.a printobj.cif __name__ == '__main__': main() 動態載入包：
def test(s,e): print s print eclass C(): def __init__(self,name): print name def test(self): print 'class!!!'
加載器代碼：
class Dynload(): def __init__(self,package,imp_list): self.package=package self.imp=imp_list def getobject(self): return __import__(self.package,globals(),locals(),self.imp,-1) def getClassInstance(self,classstr,*args): return getattr(self.getobject(),classstr)(*args) def execfunc(self,method,*args): return getattr(self.getobject(),method)(*args) def execMethod(self,instance,method,*args): return getattr(instance,method)(*args)#Test:dyn=Dynload('util.common',['*'])ins=dyn.getClassInstance('C','gao')dyn.execMethod(ins,'test')dyn.execfunc('test','Hello','function!') 根據名字加載指定文件
def loadapp(self, app): filepath="mgr/"+app+".py" if os.path.exists(filepath): imp.load_source("TYACMgrHandler_"+app.upper(), filepath)//修改了app.py，從新調用這個函數，新的代碼自動生效 根據名字調用對應方法
return getattr(self, op)(args.get("port"), args) //op="start" args=dictgetattr(self, self.request.method.lower())(*args, **kwargs) 
