python反射机制内置函数及场景构造详解_python

# commons.py
def login():
    print("这是一个登陆页面！")
def logout():
    print("这是一个退出页面！")
def home():
    print("这是网站主页面！")

# visit.py
import commons
def run():
    inp = input("请输入您想访问页面的url：  ").strip()
    if inp == 'login':
        commons.login()
    elif inp == 'logout':
        commons.logout()
    elif inp == 'index':
        commons.home()
    else:
        print('404')
if __name__ == '__main__':
    run()

import commons
def run():
    inp = input("请输入您想访问页面的url：  ").strip()
    if hasattr(commons, inp):
        getattr(commons, inp)()
    else:
        print("404")
if __name__ == '__main__':
    run()

def getattr(object, name, default=None): # known special case of getattr
    """
    getattr(object, name[, default]) -> value
    Get a named attribute from an object; getattr(x, 'y') is equivalent to x.y.
    When a default argument is given, it is returned when the attribute doesn't
    exist; without it, an exception is raised in that case.
    """
    pass

def hasattr(*args, **kwargs): # real signature unknown
    """
    Return whether the object has an attribute with the given name.
    This is done by calling getattr(obj, name) and catching AttributeError.
    """
    pass

def setattr(x, y, v): # real signature unknown; restored from __doc__
    """
    Sets the named attribute on the given object to the specified value.
    setattr(x, 'y', v) is equivalent to ``x.y = v''
    """
    pass

def delattr(x, y): # real signature unknown; restored from __doc__
    """
    Deletes the named attribute from the given object.
    delattr(x, 'y') is equivalent to ``del x.y''
    """
    pass

# user.py
def add_user():
    print('添加用户')
def del_user():
    print('删除用户')

# commons.py
def login():
    print("这是一个登陆页面！")
def logout():
    print("这是一个退出页面！")
def home():
    print("这是网站主页面！")

# visit.py
def run():
    inp = input("请输入您想访问页面的url：  ").strip()
    # modules代表导入的模块，func代表导入模块里面的方法
    modules, func = inp.split('/')
    obj_module = __import__(modules)
    if hasattr(obj_module, func):
        getattr(obj_module, func)()
    else:
        print("404")
if __name__ == '__main__':
    run()

|- visit.py
|- commons.py
|- user.py
|- lib
    |- __init__.py
    |- connectdb.py

# connectdb.py
def conn():
    print("已连接mysql")

# visit.py
def run():
    inp = input("请输入您想访问页面的url：  ").strip()
    # modules代表导入的模块，func代表导入模块里面的方法
    modules, func = inp.split('/')
    obj_module = __import__('lib.' + modules)
    if hasattr(obj_module, func):
        getattr(obj_module, func)()
    else:
        print("404")
if __name__ == '__main__':
    run()

def __import__(name, globals=None, locals=None, fromlist=(), level=0): # real signature unknown; restored from __doc__
    """
    __import__(name, globals=None, locals=None, fromlist=(), level=0) -> module
    Import a module. Because this function is meant for use by the Python
    interpreter and not for general use, it is better to use
    importlib.import_module() to programmatically import a module.
    The globals argument is only used to determine the context;
    they are not modified.  The locals argument is unused.  The fromlist
    should be a list of names to emulate ``from name import ...'', or an
    empty list to emulate ``import name''.
    When importing a module from a package, note that __import__('A.B', ...)
    returns package A when fromlist is empty, but its submodule B when
    fromlist is not empty.  The level argument is used to determine whether to
    perform absolute or relative imports: 0 is absolute, while a positive number
    is the number of parent directories to search relative to the current module.
    """
    pass

# visit.py
def run():
    inp = input("请输入您想访问页面的url：  ").strip()
    # modules代表导入的模块，func代表导入模块里面的方法
    modules, func = inp.split('/')
    # 只新增了fromlist=True
    obj_module = __import__('lib.' + modules, fromlist=True)
    if hasattr(obj_module, func):
        getattr(obj_module, func)()
    else:
        print("404")
if __name__ == '__main__':
    run()

def getf(module, func):
    """
    抽出公共部分
    """
    if hasattr(module, func):
        func = getattr(module, func)
        func()
    else:
        print('404')
def run():
    inp = input("请输入您想访问页面的url：  ").strip()
    if len(inp.split('/')) == 2:
        # modules代表导入的模块，func代表导入模块里面的方法
        modules, func = inp.split('/')
        obj_module = __import__(modules)
        getf(obj_module, func)
    elif len(inp.split("/")) == 3:
        p, module, func = inp.split('/')
        obj_module = __import__(p + '.' + module, fromlist=True)
        getf(obj_module, func)
if __name__ == '__main__':
    run()