Python -- similarities and differences among various data types

character string , list , Tuples , Mutual transformation and difference between sets .

str1 = 'helloworld'
print(str1)
# String to list ,list()
list1 = list(str1)
print(list1)
# String to tuple ,tuple()
tup = tuple(str1)
print(tup)
# List tuple 
tup1 = tuple(list1)
print(tup1)
# String conversion ,set()
set1 = set(str1)
print(set1)# There are no duplicate elements in the set 
# List to set 
set2 = set(list1)
print(set2)
# Tuple to set 
set3 = set(tup)
print(set3)

helloworld
['h', 'e', 'l', 'l', 'o', 'w', 'o', 'r', 'l', 'd']
('h', 'e', 'l', 'l', 'o', 'w', 'o', 'r', 'l', 'd')
('h', 'e', 'l', 'l', 'o', 'w', 'o', 'r', 'l', 'd')
{
'd', 'o', 'e', 'h', 'r', 'l', 'w'}
{
'd', 'o', 'e', 'h', 'r', 'l', 'w'}
{
'd', 'o', 'e', 'h', 'r', 'l', 'w'}

 Data type comparison character string list Tuples Dictionaries aggregate
Is it orderly yes yes yes no no
Modifiable or not no yes No yes yes

Variable type and immutable type
Variable type , Values can change ：

1. list list
2. Dictionaries dict
3. aggregate set

Immutable type , Value cannot be changed ：

1. value type int, long（Python3 Remove ）, bool, float
2. character string str
3. Tuples tuple