python通过字符串类型的函数名调用函数

python通过字符串类型的函数名调用函数

• eval

  def func():
      print("hello world")
  
  
  if __name__ == '__main__':
      str01 = "func"
      str_2_func = eval(str01)
      str_2_func()  # hello world
      print(type(str_2_func))  # <class 'function'>
  
  

• locals()和globals()

  def func01():
      print("hello world func01")
  
  
  def func02():
      print("hello world func02")
  
  
  if __name__ == '__main__':
      locals()['func01']()  # hello world func01
      globals()['func02']()  # hello world func02
  
  

• getattr()

  # python的内建函数，getattr(object,name)相当于object.name
  
  class A(object):
      def to_eat(self):
          print("eat")
  
      def to_sleep(self):
          print("sleep")
  
  
  if __name__ == "__main__":
      a = A()
      # 参数1：object 对象
  	# 参数2：name 方法名的字符串类型
      func01 = getattr(a, "to_eat")
      func01()
      func02 = getattr(a, "to_sleep")
      func02()
  
  

• operator中的methodcaller函数

  # 标准库operator中的methodcaller函数，同样的如果方法不存在会抛出AttributeError异常
  
  from operator import methodcaller
  
  
  class A(object):
      def func(self):
          print("func")
  
  
  if __name__ == '__main__':
      a = A()
      # methodcaller(方法名的字符串类型)(实例对象)
      methodcaller("func")(a)