python basics-list

1. List creation

new_list1 = ['TV','Car','Cloth','Food']
new_list2 = list(['TV','Car','Cloth','Food'])
print (new_list1)
print (new_list2)
Operating results:
['TV', 'Car', 'Cloth', 'Food']
['TV', 'Car', 'Cloth', 'Food']

2. List commonly used methods:

1. append

new_list1 = ['TV','Car','Cloth','Food']
print (new_list1)
new_list1.append('Water') # Append 'water'
print (new_list1)
Operating results:
['TV', 'Car', 'Cloth', 'Food']
['TV', 'Car', 'Cloth', 'Food', ' Water']

2.count

new_list1 = ['TV','Car','Cloth','Food','Food']
print (new_list1.count('Food')) #Statistics'food 'Number of times in the list => 2 times

3.extend

new_list1 = ['TV','Car','Cloth','Food','Food']
new_list1.extend([11, 22,33,'Car'])
print (new_list1)
Operating results:
['TV', 'Car', 'Cloth', 'Food', 'Food', 11, 22, 33, 'Car']

4.sort

new_list1 = ['TV','Car','Cloth','Food','Food']
print (new_list1)
new_list1.sort() #Forward sort
print (new_list1 )
new_list1.sort(reverse=True) #Reverse sort
print (new_list1)
Operating results:
['TV', 'Car', 'Cloth', 'Food', 'Food']
['Car' , 'Cloth', 'Food', 'Food', 'TV'] #Forward sorting results
['TV', 'Food', 'Food', 'Cloth', 'Car'] #Reverse sorting results

5. len

new_list1 = ['TV','Car','Food','Cloth','Food']
print (len(new_list1)) => 5 #Print the number of elements

6.remove

new_list1 = ['TV','Car','Food','Cloth','Food']

new_list1.remove('Food')
print (new_list1)
Run result:
[ 'TV', 'Car', 'Cloth', 'Food'] #remove will delete the first identical element found

7.pop

new_list1 = ['TV','Car','Food', 'Cloth','Food']
new_list1.pop() #Delete an element randomly
print (new_list1)
new_list1.pop(2) #Specify to delete an element
print (new_list1)
The operation result is:
[' TV', 'Car', 'Food', 'Cloth']
['TV', 'Car', 'Cloth'] #, what is deleted here is the third element 'Food'

8.index

new_list1 = ['TV','Car','Food','Cloth','Food']
print (new_list1.index('Food')) #Return the index value of the specified element, and return the found element for the same element The first
running result is: 2

9.insert

new_list1 = ['TV','Car','Food','Cloth','Food']
new_list1.insert(2,'HAHAHA' ) #Insert element into the specified position
print (new_list1)
The operation result is:
['TV', 'Car', 'HAHAHA', 'Food', 'Cloth', 'Food']