Example Analysis of deletion and copy of python Dictionary
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Delete and copy clear function of dictionary
The function of the clear function: to clear the existing data in the current dictionary
Usage of clear function: dict.clear (), no parameters, no return value
Examples are as follows:
User = {'name':'Neo',' age':18, 'birthday':'2000-01-01'} user.clear () print (user) # the execution result is as follows: # > {} pop function
The function of the pop function: delete the key specified in the dictionary, return its result, and report an error if the key does not exist.
The usage of the pop function: dict.pop (key), delete the key specified in parentheses and return the value corresponding to this key.
Examples are as follows:
User = {'name':'Neo',' age':18, 'birthday':'2000-01-01'} pop_value = user.pop ('birthday') print ('\ 'pop_value\' deleted\ 'value\' of\ 'birthday\' is:', pop_value,'\ 'user\' dictionary is:' User) # the execution result is as follows: # > 'pop_value'' value' is: 2000-01-01 'user' dictionary is: {' name': 'Neo',' age': 18} del function
Function of the del function: delete the key specified in the dictionary or delete the entire dictionary
Usage of del function: del dict ['key'], del dict
Examples are as follows:
User = {'name':'Neo',' age':18, 'birthday':'2000-01-01'} del user ['birthday'] print ('\ 'user\' dictionary is:', user) # the execution result is as follows: # > 'user' dictionary is: {' name':'Neo', 'age':18} del userprint (user) # execution result is as follows: # > NameError: name' user' is not defined. Did you mean: 'super'?# the user variable here has been completely deleted from the copy function
The function of the copy function: copy the current dictionary to a new dictionary, which does not share the same memory address as the original dictionary.
Usage of the copy function: dict.copy (), which takes no arguments and returns a dictionary with exactly the same content but a different memory address.
Examples are as follows:
Old_user = {'name':' Neo', 'age': 18,' birthday': '2000-01-01'} new_user = old_user.copy () print (old_user) print (new_user) # the execution result is as follows: # > > {'name':' Neo', 'age': 18,' birthday': '2000-01-01'} # > > {'name':' Neo', 'age': 18 'birthday':' 2000-01-01'} print (the memory address of'"old_user" is:', id (old_user),'"new_user" is:', id (new_user)) # the execution result is as follows: the memory address of "old_user" is: 140464840867968 "new_user": 140464841281088 is all the contents of the article "sample Analysis of deletion and copy of python Dictionary" Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!
