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This article mainly introduces the example analysis of Python list operation, the article is very detailed, has a certain reference value, interested friends must read it!

Preface

Multiple objects with different data types can be stored in the list

The memory space of an object:

So the memory space for a list is:

A = 10lst = ['hello',' a', 'world'] print (lst) print (type (lst)) print (id (lst)) print (' lst [0] type:', type (lst [0]))

I. the creation of the list:

Memory schematic diagram:

# the first way to create a list: lst = ['hello','world','52525'] print (lst) # the second way to build the function list () lst1 = list [' nice','to','meet','you'] # is not list [] print (lst1) lst2 = list (['nice','to','meet','you']) print (lst2) print ("lst2 [0]:" Lst2 [0]) print ("lst2 [- 4]:", lst2 [- 4])

Second, the characteristics of the list:

3. Query operation

# query print (lst.index ('52525')) # find print in a certain range (lst.index (4p0Pol 5)) # index is value,start,stop, respectively

Get multiple elements in the list: slicing operation

Slice result! It is equivalent to returning a new list of elements of the original list.

Lst = ['hello','world','52525',123,4,2] print (lst) print (lst [0:3]) print (LST [0: 4:2])

Note: when the x:x:-x, that is, the step size is negative, it is equivalent to start from back to front

Print ("step size is negative") print (lst [::-1]) print (LST [3: 1 print]) 4. Traversal of the list: lst = ['hello','world','52525',123,4,2] print (lst) for item in lst: print (item)

5. Additions, deletions and modifications of list elements (1) increase

Memory process of append ()

Lst = ['hello','world','52525',123,4,2] print (lst,id (lst)) lst.append (100) print (lst,id (lst)) # you can see that the address has not changed lst1 = [' new list' 'to insert'] lst.append (lst1) # insert lst1 as an element in the list lst (append can insert only one element) print (lst) lst.extend (lst1) # insert multiple elements print (lst) lst.insert (0Magne90) # insert (index,value) print (lst) # slice lst3 = ['True','False','List'] lst [1:] = lst3print (lst) at the end of the lst

(2) deletion

Lst = ['hello','world','52525',123,4,2] print (' remove delete:') print (lst) lst.remove ('hello') # Delete a specified element print (lst) print (' pop delete:') # pop () delete lst.pop (1) # delete '5252'print (lst) print (' slice delete (generate new list):') # slice # A new list object is generated at this time Does not meet our expectations new_list = lst [1:4] print ("new_list:", new_list) print (lst) print ('slice deletion (does not produce a new list) Delete the original list and replace it with []):') # there is no need to generate a new list, explain the original list with multiple elements lst [1:4] = [] print (lst)

VI. List generation

List generation is required only if there are certain rules for the elements in the list.

# list generation lst = [i for i in range (0Magne11)] print (lst) lst = [iTuni for i in range (0Magne11)] print (lst)

The above is all the contents of the article "sample Analysis of Python list Operation". Thank you for reading! Hope to share the content to help you, more related knowledge, welcome to follow the industry information channel!

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