Detailed introduction to tuples of Python data types

This article brings you a detailed introduction to the tuples of Python data types. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

1. The concept of tuple

• A tuple in python is a collection of ordered elements. The difference from a list is that a tuple is immutable. Once defined, it cannot be modified;

• Remember that tuples are immutable;

2. Definition of tuple

• You can use tuple() or () to directly initialize the tuple;

• When defining a tuple of a single element, you need to Add a comma after the element, such as t = (1,);

3. Tuple access

t = (1,2,3,4,5,6,7)
print(t[2])    #输出3

• Access to tuples is similar to lists, and can be accessed through indexes;

4. Tuple modification

• Since tuples cannot be modified, there is no way to add, delete, modify or check tuples, which also reflects the immutability of tuples;

5. Named tuple

from collections import namedtuple
Point = namedtuple('Point',['a','b'])
point = Point(1, 2)
print(point.a)    #输出１
print(point.b)    #输出2　

• Before using it, you need to import a namedtuple class through the collection module;

• Construct a tuple class: Class name = namedtuple('class name', [Iterable object]) ;

• ## Initialize tuple Example;

• Access tuples (

  tuples are also accessed through dot syntax);

##6. Bubble sorting

lst = list([1,2,7,6,3,5,4])
print(lst)  #输出[1, 2, 7, 6, 3, 5, 4]

for i in range(len(lst)):      #有多少元素则需要排序多少次
    for j in range(len(lst) - i - 1):   
        if lst[j] > lst[j+1]:    #使元素交换位置
            tmp = lst[j]
            lst[j] = lst[j+1]
            lst[j+1] = tmp
 print(lst)   #输出[1, 2, 3, 4, 5, 6, 7]

Compares two adjacent elements,
• The larger one is placed

  , and ultimately the largest element should be placed in the queue At the end;

After each comparison, the next comparison will be reduced by one;
Bubble sorting has two levels of loops. The layer loop controls the number of comparisons, and the inner loop is used to compare the size of elements;

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