Beginning Python from Novice to Professional (3)-list operation

List operations

List function:

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1. >>> list (' Hello ')
2. [' h ', ' e ', ' l ', ' l ', ' o ']

Change the list:

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1. >>> x=[1,1,1]
2. >>> x[1]=2
3. >>> x
4. [1, 2, 1]

To delete an element:

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1. >>> names = [' Wu ',' Li ', 'Zhao ',' Qian ']
2. >>> del names[1]
3. >>> names
4. [' Wu ', ' Zhao ', ' Qian ']

Shard Assignment:

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1. >>> name = List (' perl ')
2. >>> Name
3. [' P ', ' e ', ' R ', ' l ']
4. >>> name[2:] = list (' ar ')
5. >>> Name
6. [' P ', ' e ', ' a ', ' R ']

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1. >>> num = [1,2,3,4,5]
2. >>> num[1:4]=[] # starts with 1 bits but does not include 4-bit
3. >>> num
4. [1, 5]

Add a new element at the end of the Append list:

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1. >>> LST = [1,2,3]
2. >>> Lst.append (4)
3. >>> LST
4. [1, 2, 3, 4]

Number of Count statistics elements:

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1. >>> [' we ',' have ',' we ', 'a ',' dog '].count (' we ')
2. 2

Extend extension list:

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1. >>> a = [1,2,3]
2. >>> B = [4,5,6]
3. >>> A.extend (b)
4. >>> A
5. [1, 2, 3, 4, 5, 6]

Index to find the location of the first occurrence:

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1. >>> sentence = [' I ',' have ',' a ',' little ',' dog ']
2. >>> Sentence.index (' little ')
3. 3

Insert inserts an object into the list:

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1. >>> num = [1,2,3,5,6,7]
2. >>> Num.insert (3,' four ')
3. >>> num
4. [1, 2, 3, ' Four ', 5, 6, 7]

Pop removes the list element, the last one by default:

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1. >>> x = [1,2,3]
2. >>> X.pop ()
3. 3
4. >>> x
5. [1, 2]
6. >>> X.pop (0)
7. 1
8. >>> x
9. [2]

Combined Append:

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1. >>> x = [1,2,3]
2. >>> X.append (X.pop ())
3. >>> x
4. [1, 2, 3]

Remove removes the first occurrence from the list:

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1. >>> x = [' to ',' is ', 'or ',' not ',' to ',' is ']
2. >>> x.remove (' be ')
3. >>> x
4. [' to ', ' or ', ' no ', ' to ', ' being ']

Reverse Reverse storage elements:

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1. >>> x = [1,2,3]
2. >>> X.reverse ()
3. >>> x
4. [3, 2, 1]

Sort order:

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1. >>> x = [4,6,2,1,7,9]
2. >>> X.sort ()
3. >>> x
4. [1, 2, 4, 6, 7, 9]

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1. >>> X.sort (reverse=True)
2. >>> x
3. [9, 7, 6, 4, 2, 1]
4. >>> X.sort (reverse=False)
5. >>> x
6. [1, 2, 4, 6, 7, 9]
   

Beginning Python from Novice to Professional (3)-list operation