text: import numpy as np
  
  def my_test(x):
     # 代码3
     print("my_test")
     return x
  
  if __name__ == "__main__":
     f = lambda x : my_test(x) # 代码1
     print(f(2))  # 代码2
     w=np.array([1,2,3])
     x=np.array([1,2,3])
     print(np.dot(x,w))
  
  '''
  f = lambda x:my_test(x)   # 代码1
  等价于
  def f(x):
  	return my_test(x)
  '''