[Python Basics (i)] Sequence operations basics

I. Data structure of Python

Container: Any object that contains other objects.

Include: sequences (such as lists, tuples), mappings (such as dictionaries), collections, and so on. Mainly sequences and mappings.

Second, sequence operation

Index, shard, add, multiply, check whether an element is a member of the sequence. Also, calculate the length of the sequence, looking for the largest, most lower element.

1. Index

Positive number: Starting from 0, left to right;

Negative number: From 1 onwards, to left

2. sharding

Two indexes as boundaries, the first index element is contained within a shard, and the second is not.

A= ' 123456789 '

Print A[2:5]

' 345 '

3. Sequence addition condition: the same type of sequence

4. Multiplication

5. Membership in operator

6. Length Len (), Max Max (), Min min ()

Third, List

1.list function: Create a list based on a string

2. Basic list Operations

Assign value
x=[1,1,1]
x[1]=2
Print X

#删除元素
name=[' x ', ' y ', ' Z ']
Del Name[2]
Print Name

#分片赋值
Name=list (' Perl ')
Name[2:]=list (' ar ')
Print Name

Name[2:]=list (' Ython ')
Print Name

numbers=[1,5]
numbers[1:1]=[2,3,4]
Print numbers

3. List method

#1. Append: Add new objects at the end of the list
lst=[1,2,3]
Lst.append (4)
Print LST

#2. Count counts the number of occurrences of an element
a=[' to ', ' to ', ' a ', ' B ', ' to ', ' C '].count (' to ')
Print a

#3. Extend add multiple values at the end of the list, which differs from the connection
a=[1,2,3]
b=[4,5,6]
A.extend (b)
Print a

#4. Index to find the first index position of a value
K=[' A ', ' B ', ' C ', ' d ']
Print K.index (' C ')

#5. Insert inserts an object into the list
ll=[1,2,3,4,5]
Ll.insert (3, ' four ')
Print LL

#6. Pop removes an element from the list, the default is the last
x=[1,2,3,4,5]
Print X.pop ()
X.pop (1)
Print X

#7. Remove removes a match for one of the values in the list
X=[' A ', ' B ', ' C ', ' B ', ' E ']
X.remove (' B ')
Print x #[' A ', ' C ', ' B ', ' E ']

#8. Reverse to store element orientation in the list
X=[' A ', ' B ', ' C ', ' B ', ' E ']
X.reverse ()
Print x #[' e ', ' B ', ' C ', ' B ', ' a ']

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

#10 CMP
Print CMP (12,10) #1
Print CMP (10,12) #0
Print CMP (10,12) #-1

Four. Tuples: Immutable sequences

1. Tuple creation: Surrounded by parentheses

(1, 2, 3)

2. The tuple function converts a sequence to a tuple
K=tuple (' abc ')
Print k # (' A ', ' B ', ' C ')

[Python Basics (i)] Sequence operations basics