OpenZeppelin provides three access control modes for smart contracts: the Ownable contract, the Roles library, and the 3.0 new AccelessControl contract.In this tutorial, we will learn about the differences among the three access control modes and how to use them to enhance the security of Solidity contracts in your own ETAI smart contracts.
Added by netfrugal on Wed, 06 May 2020 00:12:49 +0300
Basic python preparation:
Fundamentals of pygame, refer to Eye Blog's "Write games with Python and Pygame - from getting started to mastering"
Install python 3.8.0 to download on python's official website, not to mention more.
Install pygame, command: pip install pygame
If the installation is slow, you can change the pip so ...
Added by rohithmr on Tue, 05 May 2020 20:13:13 +0300
Python control keyboard and mouse: pynput
This library allows you to control and monitor input devices.
For each input device, it contains a sub package to control and monitor the input device:
pynput.mouse: a class that controls and monitors the mouse or touchpad.
pynput.keyboard: a class that ...
Added by Stalingrad on Tue, 05 May 2020 05:34:26 +0300
On the previous blog: Introduction to CNN network in the introduction series of data mining (11.5) In this blog, we will use code to explain how to use keras to build a CNN network to train CIFAR-10 dataset.
If you are not familiar with keras, you can take a look Official documents . Or take a look at my previous blog: Int ...
Added by mjohnson025 on Mon, 04 May 2020 06:47:25 +0300
Find a local file first
Open file, read file string
Create an object att through the MIMT ext() class, and pass in the file to read the content
Add the header information of att and specify the file name
Add to MSG message msg.attach(att)
attfile = 'test.py'
basename = os.path.basename(attfile)
Added by ajaybuilder on Sun, 03 May 2020 22:28:26 +0300
Creating Python functions
# Return value of function
# Return value of function,No return defined None,
# There is a return value that returns this object(You can return a function object),
# More than one returns a tuple
Calls to Python functions
Arguments to Python functi ...
Added by studgate on Sun, 03 May 2020 07:58:40 +0300
Because it is often necessary to operate on a json format file, it is more difficult to edit the text. I want to write a script to operate on the file, and send the modified file directly to the mailbox
The file directory is as follows:
drwxr-xr-x 2 root root 4096 12 29 / 16:14 backup
-rw-r--r-- 1 root root 168 12 29 / 16:10 config.ini
Added by tex1820 on Sun, 03 May 2020 00:01:36 +0300
I defined a simple business card management system as a function..
A login interface;
A business card management system user interface;
The logic is: login succeeded =, jump into the card system user interface, and at the same time, jump out of the login interface, give welcome to use, and the program ends.
At this time, the problem i ...
Recently, the entertainment industry can be said to be bustling. Before, there was a bully president who loved Xiao San, the palace was torn and forced to be a red girl in the net, and after that, there was a sunny boy named Show Luo, who was robbed of his reputation by Zhou Yangqing. It's hard for ordinary people to understand th ...
Added by r_a_s_robin on Sat, 02 May 2020 03:07:36 +0300