Python custom exceptions and common exception types

To try… Except… The else… finally

def self_error(type_list) :
 The exception handler passes an iterable and handles the error case of passing parameters: paramType_list: an iterable """
 try:
 for i in type_list:
  print(i)
 except:
 print("Not an iterable")
 else:
 print("No error occurred.")
 finally:
 print("Program completed")
self_error("abc")
"" no error occurs in a, B, and C. The program is finished. ""
self_error(2)
"" not an iterable program ends running """
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It can be seen from the program that if the try part is executed successfully, the else part is executed, and if the try part is in error, the except part is executed, but in both cases the finally part is printed. Of course, the else and finally parts can be omitted. We can customize the output error type by using the raise function.

#Python Learning exchange QQ group: 531509025

def self_error(type_num) :
  """ Exception handler Function A user-defined exception handler used to throw an exception :paramtype_num: Value used to check whether an exception is thrown :return Exception information """
  if type_num<10:
   raise ValueError("Value less than 10")
  else:return 200
 if __name__=="__main__":
 self_error(11) # 200
 self_error(9) #ValueError: The value is less than 10
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Raise raises exceptions that only apply to Python’s standard exception classes