Python data structure
beginning
The following code is completed in the interactive interface (you can also write the code into the script, you need to add print(...) to display):
The interactive command prompt of python is:
>>>The content entered after this symbol will run in real time and display the results of the run.
For example, if we enter 2 it will produce the following changes:
>>> 2
2
>>> We enter 2, and python reads 2 as a number, and then returns the entered number, which is 2.
What if we enter a Formula?
>>> 1+2
3
>>> Python will calculate the corresponding value.
Python contains algorithms that can perform scientific calculations. For example, if you enter:
>>> 7+3*7/5+5/3+(11*9+2)/5
33.06666666666666
>>> Python will perform operations based on the priority of arithmetic symbols.
Python can also directly perform large number operations, you can calculate any number less than 1e10000:
Where ** means to calculate the power.
We can use the type() function to observe the data type:
2 is an integer.
There are six data types in Python: Numbers, strings, lists, tuples, sets, dictionaries. Let's explain each data type in next a few chapter.
Classified according to whether it contains a hash table
Numbers, strings, lists, tuples do not use hash table indexes.
sets, dictionaries use hash table index.
When introducing the data structure, we will use whether to include a hash table to introduce separately.
Variable and immutable
Numbers, strings, tuples are immutable.
lists, sets, dictionaries are variable.
I will talk about the difference between Variable and Immutable in a later chapter.
Statistics
Start time of this page: December 18, 2021
Completion time of this page: December 18, 2021
Last updated