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Python Is an easy to learn 、 Powerful programming language . It provides an efficient high-level data structure , It's also a simple and effective way of object-oriented programming .Python Elegant grammar and dynamic typing and the essence of interpretive language , Make it an ideal language for scripting and rapid application development on most platforms . Now let's introduce python Basic operations for lists , About adding and deleting syntax .
Use append() Method to add a new element to the end of the list , The format is as follows .
list.append(obj)
for example ：
add_list = [0, 1, 2, 3] # Create a list of add_list And the assignment
add_list.append(4) # Use append() Methods add_list Add element at end 4
print(add_list)
give the result as follows .
Use extend() Method can append multiple values in another sequence at the end of the list at one time , The format is as follows .
list.extend(seq)
example ： Compare extend() Methods and append() Method to add list elements .
list_1 = [1, 2, 3] # Create a list of list_1 And the assignment
list_2 = [4, 5, 6] # Create a list of list_2 And the assignment
list_3 = [7, 8, 9] # Create a list of list_3 And the assignment
list_1.append(list_2) # take list_2 As an object , The whole package is added to list_1 In the object
print(list_1) # Output list_1
list_2.extend(list_3) # take list_3 As a sequence , Combine this sequence with list_2 Sequence merging
print(list_2) # Output list_2
give the result as follows .
del command ： The elements in the list can be deleted according to the index , You can also use fragmentation to delete elements in the list ..
list.index(obj)
example ： Find elements in the list , If you find , Output the index position of the element in the list , Otherwise, the output is not found .
number = [1,2,3,4,5] # Create a list of number And the assignment
del number[2] # Use del Command deletion number The index for 2 The elements of
print(number)
number = [1,2,3,4,5] # Create a list of number And the assignment
del number[1:3] # Use del Delete index from command 1 To 3（ barring 3） The elements of
print(number)
give the result as follows .
Used to remove an element from the list （ Default to last element ）, And returns the value of that element , The format is as follows .
list.pop([obj])
for example ：
number = [1, 2, 3, 4, 5] # Create a list of number And the assignment
print(number.pop()) # Use pop() Methods to remove number The elements in
print(number)
print(number.pop(0)) # Use pop() Methods to remove number The index for 0 The elements of
print(number) # Print number
give the result as follows .
Used to remove the first match of a value in the list , The format is as follows .
list.remove(obj)
example ： Delete all specified elements in the list .
x = ['123', 'abc', 'xyz', 'abc', 'python'] # Create a list of x And the assignment
while 'abc' in x: # loop
x.remove('abc') # Use remove() Methods to remove x The median is 'abc' The elements of
print(x) # Output x
give the result as follows .
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The above is about Python Basic operations for lists , About adding and deleting syntax , You can refer to it , Relevant knowledge will be continuously updated later , Make progress together .
